Hydrogen generation system

Abstract

The present disclosure relates to compositions, systems, and methods that enable the electrochemical conversion of ammonia into hydrogen and nitrogen gases under mild operating conditions, including ambient temperature and pressure. This approach addresses key limitations of conventional ammonia thermal cracking, including the need for high temperatures and pressures and complex downstream gas separation, while overcoming media and catalyst constraints in electrolytic cracking of ammonia.

Description

WSGR Docket No.70778-702.601 HYDROGEN GENERATION SYSTEM CROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application No.63 / 696,315, filed September 18, 2024, which is incorporated by reference herein in its entirety. STATEMENT AS TO FEDERALLY SPONSORED RESEARCH

[0002] This invention was made with government support under NSF SBIR Award No.2423448 awarded by the National Science Foundation. The government has certain rights in the invention. BACKGROUND

[0003] Conventional approaches to generating hydrogen using ammonia, such as thermal cracking, typically require high temperatures and pressures, making them energy intensive and costly, and also involve various technical challenges. SUMMARY

[0004] To address the challenges associated with the generation of hydrogen using ammonia, the present disclosure provides a new approach to use ammonia as a hydrogen carrier in electrolysis systems without the need for external pressurization, refrigeration, or dissolution in water or solvent media. This method provides ammonia liquefiers configured to convert gaseous or liquid- phase ammonia into a liquefied form suitable for electrochemical hydrogen production. The liquefied ammonia typically exhibits lower vapor pressure and higher boiling or melting points than pure ammonia, allowing the process to be carried out under ambient or near-ambient conditions.

[0005] Provided herein is a system comprising: (i) an ammonia preparation unit comprising a liquefier configured to stabilize ammonia in liquid state, wherein the liquefier comprises one or more compounds of the formula AnQm, wherein A is a first moiety comprising lithium (Li), sodium (Na), hydrogen (H), guanidinium (CH6N3+), ammonium (NH4+), or one or more atoms from Group 16 of periods 3, 4, 5, or 6 of the Periodic Table of Elements; Q is a second moiety comprising at least one atom selected from the group consisting of boron (B), Group 15, or Group 16 of periods 3, 4, 5, or 6, or a combination thereof, wherein, when A is guanidium (CH6N3+), Q comprises one or more atoms from Group 17; n is an integer from 1 to 4; and m is an integer from 1 to 4; and (ii) an electrochemical cell configured to convert liquid ammonia into hydrogen and nitrogen.WSGR Docket No.70778-702.601

[0006] In some embodiments, the liquefier is configured to stabilize ammonia in a liquid state upon contact with ammonia, thereby forming a complex of the formula (AnQm)(NH3)y, wherein y is a number ranging from 1 to 8.

[0007] In some embodiments, Q comprises -BF4, -SCN, -SeCN, -NO3, -CF3SO3, -PF6, -ClO4, - C4F9SO3, -CH3CO2, -N(SO2F3)2, -NH2, -N3, or -SbF6.

[0008] In some embodiments, the one or more of compounds of formula AnQmare selected from a group consisting of NaSCN, HSCN, NH4SCN, NH4SeCN, NaSeCN, (CH6N3)SCN (guanidinium thiocyanate), NH4NO3, NaNO3, (CH6N3)NO3(guanidinium nitrate), LiSCN, LiSeCN, NH4ClO4, NH4C4F9SO3, (CH6N3)I (guanidinium iodide), (CH6N3)BF4(guanidinium tetrafluoroborate), NH4CH3CO2, NH4N(SO2F3)2, (CH6N3)PF6 (guanidinium hexafluorophosphate), (CH6N3)(CF3SO3) (guanidinium trifluoromethanesulfonate), SO2(NH2)2, I2, SO2(NH2)(NC6H5), and SeO2(NH2)2. In some embodiments, the one or more compounds of formula AnQm comprises sodium thiocyanate (NaSCN), ammonium thiocyanate (NH₄SCN), sulfamide (SO₂(NH₂)₂), lithium thiocyanate (LiSCN), guanidinium thiocyanate ((CH₆N₃)SCN), or guanidinium trifluoromethanesulfonate (guanidinium triflate).

[0009] In some embodiments, the complex is present in a liquid or gel phase. In some embodiments, the complex is present in a liquid or gel phase under ambient temperature and ambient pressure. In some embodiments, the complex remains in liquid form across pressures in the range of about 0.001 to about 15 atm. In some embodiments, the complex remains in liquid form at temperatures ranging from about -30 °C to about 120 °C.

[0010] In some embodiments, the liquefier serves as an electrolyte.

[0011] In some embodiments, the AnQmor (AnQm)(NH3)yis mixed with a electrolyte in the ammonia preparation unit. In some embodiments, the electrolyte enhances ionic conductivity of the liquid ammonia. In some embodiments, the electrolyte comprises ammonium triflate (NH₄OTf), ammonium tetrafluoroborate (NH₄BF₄), ammonium hexafluorophosphate (NH₄PF₆), or sodium triflate (NaOTf). In some embodiments, the electrolyte is selected from a group consisting of ammonium halides (NH4L), wherein L is I, Br, and Cl, or multiatomic moiety comprising at least one atom from group 15, 16, and 17 of periodic table comprising CF3SO3- or PF6-. In some embodiments, the electrolyte is selected from a group consisting of sodium chloride (NaCl), sodium bromide (NaBr), potassium bromide (KBr), potassium chloride (KCl), potassium nitrate (KNO₃), lithium nitrate (LiNO₃), sodium nitrate (NaNO₃), ammonium nitrate (NH₄NO₃), ammonium Chloride (NH₄Cl), ammonium Bromide (NH₄Br), ammonium iodide (NH₄I), alkyl chloride (RCl), potassium hexafluorophosphate (KPF6), ammonium hexafluorophosphate (NH4PF6), sodium hexafluorophosphate (NaPF6), ammonium triflateWSGR Docket No.70778-702.601 (NH4CF3SO3), and sodium triflate (NaCF3SO3) . In some embodiments, the electrolyte comprises lithium amide (LiNH2), ammonium amide (NH4NH2), potassium amide (KNH2), sodium sulfate (Na2SO4), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), or potassium hydroxide (KOH). In some embodiments, the electrolyte is selected from a group consisting of alkali metals in their cationic or metallic forms comprising Li+or Li, ammonium cation, alkylammonium cation, halide ions, alkyl amines, nitrite, nitrate, phosphate, polyphosphate, perchlorate, silicate, sulfate, carbonate, borate, or tetraalkyl ammonium. In some embodiments, the electrolyte is selected from a group consisting of hydrazinium chloride (N2H5Cl), hydrazinium bromide (N2H5Br), hydrazinium acetate, hydrazinium azide, and a derivative of hydrazine.

[0012] In some embodiments, the system further comprises an ammonia source unit configured to supply ammonia feedstock.

[0013] In some embodiments, the ammonia preparation unit is further configured to deliver liquid ammonia or the complex to the electrochemical cell. In some embodiments, the electrochemical cell comprises an anodic compartment and a cathodic compartment.

[0014] In some embodiments, the anodic compartment comprises an anode and an anolyte. In some embodiments, the anolyte comprises one or more electrolytes. In some embodiments, liquid ammonia serves as a sole anolyte. In some embodiments, the anodic compartment is configured to facilitate an oxidation of ammonia through the ammonia oxidation reaction (AOR).

[0015] In some embodiments, the anodic compartment comprises an ammonia oxidation reaction (AOR) catalyst comprising one or more metals selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), chromium (Cr), platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh), and manganese (Mn), or a combination or an alloy thereof. In some embodiments, the AOR catalyst comprises a composition comprising platinum (Pt) and one or more additional metals. In some embodiments, the one or more additional metals are selected from the group consisting of iridium (Ir), cobalt (Co), iron (Fe), copper (Cu), ruthenium (Ru), rhodium (Rh), manganese (Mn), and nickel (Ni). In some embodiments, the AOR catalyst is configured as a binary, ternary, multi-metallic, or heterogeneous composite. In some embodiments, the AOR catalyst is present in an elemental form, an alloy, or a chemically bound form. In some embodiments, the chemically bound form of the AOR catalyst comprises oxides, nitrides, phosphides, carbides, selenides, borides, hydroxides, or a combination thereof. In some embodiments, the AOR catalyst comprises platinum (Pt) and one or more additional metals, wherein the one or more additional metals are present at a molar ratio relative to Pt in the range of about 0.1:1 to about 10:1. In some embodiments, the AOR catalyst comprises a binary alloy ofWSGR Docket No.70778-702.601 platinum (Pt) and iridium (Ir), wherein a molar ratio of Pt to Ir ranges from about 1:1 to about 10:1. In some embodiments, the AOR catalyst comprises platinum (Pt), iridium (Ir), and nickel (Ni). In some embodiments, the AOR catalyst is a binary (Pt–Ni, Ir–Ni) or multi-metallic composition (Pt–Ir–Ni). In some embodiments, Ni is present in the catalyst at a molar ratio of about 0.1:1 to about 10:1 relative to Pt or to the combined Pt and Ir content.

[0016] In some embodiments, the AOR catalyst comprises an iron-based alloy comprising one or more atoms selected from chromium (Cr), nickel (Ni), carbon (C), manganese (Mn), and optionally molybdenum (Mo). In some embodiments, the AOR catalyst comprises an alloy comprising iron, nickel, chromium, and carbon. In some embodiments, iron is present in the AOR catalyst at about 60 wt.% to about 90 wt.% of the AOR catalyst. In some embodiments, nickel is present in the AOR catalyst at about 0.1 wt.% to about 20 wt.%. In some embodiments, chromium is present in the AOR catalyst at about 8 wt.% to about 25 wt.%. In some embodiments, carbon is present in the AOR catalyst at about 0.05 wt.% to about 2.1 wt.%.

[0017] In some embodiments, the AOR catalyst further comprises manganese (Mn) or molybdenum (Mo). In some embodiments, the AOR catalyst further comprises manganese (Mn) and molybdenum (Mo). In some embodiments, Mn is present in the AOR catalyst at about 0.1 wt.% to about 13.0 wt.%. In some embodiments, Mo is present in the AOR catalyst at about 0.1 wt.% to about 3.0 wt.%.

[0018] In some embodiments, a surface of the AOR catalyst is modified to enhance catalytic activity toward ammonia oxidation. In some embodiments, the surface of the AOR catalyst is modified by one or more methods selected from the group consisting of mechanical polishing, sandblasting, plasma treatment, laser etching, electrochemical activation, and chemical etching.

[0019] In some embodiments, the cathodic compartment comprises a cathode and a catholyte. In some embodiments, the cathodic compartment further comprises a hydrogen evolution reaction (HER) catalyst. In some embodiments, the HER catalyst comprises at least one metal selected from a group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), platinum (Pt), palladium (Pd), iridium (Ir), ruthenium (Ru), rhodium (Rh), manganese (Mn), molybdenum (Mo), and gold (Au), or an alloy or a combination thereof. In some embodiments, the HER catalyst comprises a monometallic, a bimetallic, or a trimetallic configuration, which one or more metals are integrated as an alloy, a layered structure, or a core–shell configuration. In some embodiments, the HER catalyst comprises a nickel alloy comprising one or more metals selected from a group consisting of iron (Fe), ruthenium (Ru), platinum (Pt), molybdenum (Mo), manganese (Mn), cobalt (Co), copper (Cu), and silver (Ag), wherein Ni content ranges from about 30 wt.% to 99 wt.%. In some embodiments, the HER catalyst comprises a platinum-basedWSGR Docket No.70778-702.601 catalyst comprising Pt supported on carbon (Pt–C). In some embodiments, the HER catalyst comprises platinum (Pt) and at least one or more additional metals selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), ruthenium (Ru), palladium (Pd), copper (Cu), and silver (Ag), wherein Pt content ranges from about 10 wt.% to about 90 wt.%.

[0020] In some embodiments, the cathodic compartment comprises an aqueous solution of one or more alkaline hydroxides comprising potassium hydroxide (KOH), sodium hydroxide (NaOH), or lithium hydroxide (LiOH). In some embodiments, the cathodic compartment further comprises a membrane or a separator configured to prevent water crossover, gas mixing, or electrolyte imbalance. In some embodiments, the catholyte comprises aqueous ammonia with one or more alkaline additives comprising KOH, NaOH, or LiOH. In some embodiments, the cathodic compartment further comprises an acidic aqueous electrolyte comprising hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), phosphoric acid (H₃PO₄), or trifluoromethanesulfonic acid (triflic acid, CF₃SO₃H).

[0021] In some embodiments, the system further comprises a power supply configured to be connected to the cathode and the anode. In some embodiments, the power supply comprises a DC source, a battery, a potentiostat, or a programmable power supply.

[0022] In some embodiments, the anodic compartment and the cathodic compartment are separated by a separator. In some embodiments, the separator comprises a membrane, porous diaphragm, or a multilayer laminate structure. In some embodiments, the separator comprises a bipolar membrane (BPM). In some embodiments, the separator is configured to allow selective ionic transport for protons (H⁺) or ammonium ions (NH₄⁺). In some embodiments, the separator is configured to facilitate ionic conduction between the compartments while preventing or minimizing the direct crossover or mixing of the anolyte and the catholyte. In some embodiments, the separator is configured to maintain gas-phase separation. In some embodiments, the separator comprises one or more of polyethylene, polypropylene, polysulfone, polyamide, polyethersulfone (PES), polyvinylidene fluoride (PVDF), polyester, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), perfluoroethylene-propylene (FEP), ethylene-tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene- chlorotrifluoroethylene (ECTFE), or polybenzimidazole (PBI). In some embodiments, the separator is fabricated into a porous, a non-porous, or a reinforced membrane structure. In some embodiments, the separator comprises one or more of sulfonated polystyrene, sulfonated polyether ether ketone (sPEEK), sulfonated polyarylether ketone (sPAEK), sulfonated polybenzimidazole (sPBI), sulfonated polysulfone, sulfonated polyetherimide, sulfonated polyetherketone, or sulfonated polyphosphazene. In some embodiments,WSGR Docket No.70778-702.601 the separator comprises one or more materials selected from the group consisting of poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), or Nafion®. In some embodiments, the separator comprises a ceramic membrane, a glass fiber filter, a porous insulating body, or a chemically stable polymer blend. In some embodiments, the porous insulating body comprises or is filled with agar, zeolite, or metal oxides. In some embodiments, the separator comprise a hydrophilic porous membrane or diaphragm configured to facilitate ionic conductivity. In some embodiments, the separator comprises a porous membrane comprising Zirfon® UPT or a polysulfone-based membrane reinforced with zirconia particles.

[0023] In some embodiments, the ammonia preparation unit further comprises one or more additives configured to increase the ionic conductivity of liquid ammonia. In some embodiments, the one or more additives are selected from a group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), propanol (C₃H₇OH), butanol (C4H10O), dimethyl sulfoxide (C₂H₆OS), glycerol (C₃H₈O₃), acetic acid (CH₃COOH), dimethylformamide (C₃H₇NO), pyridine (C₅H₅N), ethylene glycol (C₂H₆O₂), methanol (CH₃OH), acetone (C₃H₆O), tetrahydrofuran (C₄H₈O), diethylamine (C₄H₁₁N), triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), acetonitrile (C2H3N), N-methyl-2- pyrrolidinone (C5H9NO), hexamethylphosphorous triamide (C6H19N3OP), nitromethane (CH3NO2), urea (CH4N2O), phenol (C6H6O), 2-pyrrolidone (C4H7NO), diisopropylamine (C6H15N), 1,4-dioxane (C4H8O2), and morpholine (C4H9NO). In some embodiments, the one or more additives are selected from a group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), glycerol (C₃H₈O₃) or triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), and ethylene glycol ((CH₂OH)₂). In some embodiments, the one or more additives are further configured to tune one or more physical properties of the liquefied ammonia, wherein the one or more physical properties comprise boiling point, vapor pressure, viscosity, solubility, or thermal stability. In some embodiments, the one or more additives are selected from group comprises 1,3,5- trinitrobenzene (C₆H₃(NO₂)₃), 2,4,6-trinitroaniline (C₆H₂(NO₂)₃NH₂), tetranitromethane (C(NO₂)₄), sodium nitromethanide (CH₂NO₂Na), ammonium nitroethane (CH₃CH₂NO₂NH₄), , nitroguanidine (CH₄N₄O₂), methyl nitramine (CH₃N₂O₂), sulfanilamide (C₆H₈N₂O₂S), cyanamide (CH₂N₂), phthalimide (C₆H₄(CO)₂NH), thiourea (CS(NH₂)₂), thiosemicarbazide (H₂NNHC(S)NH₂), benzamide (C₆H₅CONH₂), phenylacetamide (C₆H₅CH₂CONH₂), cyanocetamide (CH₂(CN)CONH₂), ethylamine hydrochloride (C₂H₅NH₂·HCl), and diethylamine ((C₂H₅)₂NH). In some embodiments, the one or more additives remain inert with both the cathodic and anodic compartment. In some embodiments, the one or more additives areWSGR Docket No.70778-702.601 configured to modify the vapor pressure of ammonia by about 5% to about 40% when in contact with ammonia. In some embodiments, the one or more additives are configured to modify the ionic conductivity of liquefied ammonia by about 2 to about 100 times when in contact with ammonia.

[0024] In some embodiments, the system further comprises a dryer configured to remove moisture from ammonia feedstock prior to introduction into the ammonia conditioning unit. In some embodiments, the electrochemical cell is integrated with one or more downstream gas management units configured to isolate product gases and recover unreacted ammonia. In some embodiments, the one or more downstream gas management units comprise gas–liquid separation modules, ammonia-selective adsorbent units, and gas purification components for hydrogen and nitrogen, or tailored to the specific operating configuration (e.g., flow-through or non-flow).

[0025] In some embodiments, the system further comprises an adsorbent unit configured to utilize one or more compounds of formula AnQm as an adsorbent medium. In some embodiments, the adsorbent medium comprises one or more compositions comprising at least one of lithium thiocyanate (LiSCN), ammonium thiocyanate (NH₄SCN), or sulfamide (NH₂SO₂NH₂).

[0026] In some embodiments, the electrochemical cell is configured for continuous-flow or batch operation. In some embodiments, the system comprises more than one electrochemical cell, wherein one or more electrochemical cells in the system are arranged in series or parallel configurations. In some embodiments, the electrochemical cell further comprises a sealing gasket, an electrical terminal, a flow port, a thermal regulation component, or a pressure or flow control element.

[0027] In some embodiments, the system further comprises a downstream gas separation unit configured to purify hydrogen produced in the electrochemical cell. In some embodiments, the system further comprises a gas–liquid separator that is positioned downstream of the anode outlet configured to isolate the nitrogen and the ammonia from liquid phase. In some embodiments, the system further comprises a second adsorbent unit configured to selectively capture residual ammonia. In some embodiments, the system further comprises a downstream gas–liquid separation and a multi-stage adsorbent-based purification configured to recover ammonia and isolate the hydrogen and nitrogen.

[0028] Provided herein is also a method comprising: (i) contacting ammonia with a liquefier comprising one or more compounds of the formula AnQmto form a liquefied ammonia, wherein A is a first moiety comprising lithium (Li), sodium (Na), hydrogen (H), guanidinium (CH6N3+), ammonium (NH4+), or one or more atoms from Group 16 of periods 3, 4, 5, and 6 of the PeriodicWSGR Docket No.70778-702.601 Table of Elements; Q is a second moiety comprising at least one atom from boron (B), Group 15, or Group 16 of periods 3, 4, 5, and 6, or a combination thereof, wherein, when A is guanidium (CH6N3+), Q comprises one or more atoms from Group 17; n is an integer from 1 to 4; and m is an integer from 1 to 4; (ii) providing the liquefied ammonia to an electrochemical cell; and (iii) applying an electric potential across the electrochemical cell to convert the ammonia into hydrogen and nitrogen.

[0029] In some embodiments, the method further comprises generating (AnQm)(NH3)y by storing the ammonia in a liquid state, wherein y is a number ranging from 1 to 8.

[0030] In some embodiments, Q comprises -BF4, -SCN, -SeCN, -NO3, -CF3SO3, -PF6, -ClO4, - C4F9SO3, -CH3CO2, -N(SO2F3)2, -NH2, -N3, or -SbF6.

[0031] In some embodiments, the one or more of compounds of formula AnQmare selected from a group consisting of NaSCN, HSCN, NH4SCN, NH4SeCN, NaSeCN, (CH6N3)SCN (guanidinium thiocyanate), NH4NO3, NaNO3, (CH6N3)NO3 (guanidinium nitrate), LiSCN, LiSeCN, NH4ClO4, NH4C4F9SO3, (CH6N3)I (guanidinium iodide), (CH6N3)BF4 (guanidinium tetrafluoroborate), NH4CH3CO2, , NH4N(SO2F3)2, (CH6N3)PF6(guanidinium hexafluorophosphate), (CH6N3)(CF3SO3) (guanidinium trifluoromethanesulfonate), SO2(NH2)2, I2, SO2(NH2)(NC6H5), and SeO2(NH2)2. In some embodiments, the one or more compounds of formula AnQm comprises sodium thiocyanate (NaSCN), ammonium thiocyanate (NH₄SCN), sulfamide (SO₂(NH₂)₂), lithium thiocyanate (LiSCN), guanidinium thiocyanate ((CH₆N₃)SCN), or guanidinium trifluoromethanesulfonate (guanidinium triflate).

[0032] In some embodiments, the complex is present in a liquid or gel. In some embodiments, the complex is present in a liquid or gel phase under ambient temperature and ambient pressure. In some embodiments, the complex remains in liquid form across pressures in the range of about 0.001 to about 15 atm. In some embodiments, the complex remains in liquid form at temperatures ranging from about -30 °C to about 120 °C.

[0033] In some embodiments, the liquefier serves as an electrolyte. In some embodiments, the method further comprises mixing the AnQm or (AnQm)(NH3)y with a supporting electrolyte in the ammonia preparation unit. In some embodiments, the electrolyte enhances ionic conductivity of the liquid ammonia. In some embodiments, the electrolyte comprises ammonium triflate (NH₄OTf), ammonium tetrafluoroborate (NH₄BF₄), ammonium hexafluorophosphate (NH₄PF₆), or sodium triflate (NaOTf). In some embodiments, the electrolyte is selected from a group consisting of ammonium halides (NH4L), wherein L is I, Br, and Cl, or multiatomic moiety comprising at least one atom from group 15, 16, and 17 of periodic table comprising CF3SO3- or PF6-. In some embodiments, the electrolyte is selected from a group consisting of sodiumWSGR Docket No.70778-702.601 chloride (NaCl), sodium bromide (NaBr), potassium bromide (KBr), potassium chloride (KCl), potassium nitrate (KNO₃), lithium nitrate (LiNO₃), sodium nitrate (NaNO₃), ammonium nitrate (NH₄NO₃), ammonium Chloride (NH₄Cl), ammonium Bromide (NH₄Br), ammonium iodide (NH₄I), alkyl chloride (RCl), potassium hexafluorophosphate (KPF6), ammonium hexafluorophosphate (NH4PF6), sodium hexafluorophosphate (NaPF6), ammonium triflate (NH4CF3SO3), and sodium triflate (NaCF3SO3). In some embodiments, the electrolyte comprises lithium amide (LiNH2), ammonium amide (NH4NH2), potassium amide (KNH2), sodium sulfate (Na2SO4), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), or potassium hydroxide (KOH). In some embodiments, the electrolyte is selected from a group consisting of alkali metals in their cationic or metallic forms comprising Li+or Li, ammonium cation, alkylammonium cation, halide ions, alkyl amines, nitrite, nitrate, phosphate, polyphosphate, perchlorate, silicate, sulfate, carbonate, borate, or tetraalkyl ammonium. In some embodiments, the electrolyte is selected from a group consisting of hydrazinium chloride (N2H5Cl), hydrazinium bromide (N2H5Br), hydrazinium acetate, hydrazinium azide, and a derivative of hydrazine.

[0034] In some embodiments, the method further comprises supplying ammonia feedstock using an ammonia source unit.

[0035] In some embodiments, the electrochemical cell comprises an anodic compartment and a cathodic compartment. In some embodiments, the anodic compartment comprises an anode and an anolyte. In some embodiments, the anolyte comprises one or more electrolytes. In some embodiments, the liquefied ammonia serves as a sole anolyte. In some embodiments, the anodic compartment facilitates an oxidation of ammonia through the ammonia oxidation reaction (AOR). In some embodiments, the anodic compartment comprises an ammonia oxidation reaction (AOR) catalyst comprising one or more metals selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), chromium (Cr), platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh), and manganese (Mn), or a combination or an alloy thereof. In some embodiments, the AOR catalyst comprises a composition comprising platinum (Pt) and one or more additional metals. In some embodiments, the one or more additional metals are selected from a group consisting of iridium (Ir), cobalt (Co), iron (Fe), copper (Cu), ruthenium (Ru), rhodium (Rh), manganese (Mn), and nickel (Ni). In some embodiments, the AOR catalyst is configured as a binary, ternary, multi-metallic, or heterogeneous composite. In some embodiments, the AOR catalyst are present in an elemental form, an alloy, or a chemically bound form. In some embodiments, the chemically bound form comprises oxides, nitrides, phosphides, carbides, selenides, borides, hydroxides, or a combination thereof.WSGR Docket No.70778-702.601

[0036] In some embodiments, the AOR catalyst comprises platinum (Pt) and one or more additional metals, wherein the one or more additional metals are present at a molar ratio relative to Pt in the range of about 0.1:1 to about 10:1. In some embodiments, the AOR catalyst comprises a binary alloy of platinum (Pt) and iridium (Ir), wherein a molar ratio of Pt to Ir ranges from about 1:1 to about 10:1. In some embodiments, the AOR catalyst comprises platinum (Pt), iridium (Ir), and nickel (Ni). In some embodiments, the AOR catalyst is a binary (Pt–Ni, Ir–Ni) or multi-metallic composition (Pt–Ir–Ni). In some embodiments, Ni is present in the catalyst at a molar ratio of about 0.1:1 to about 10:1 relative to Pt or to the combined Pt and Ir content.

[0037] In some embodiments, the AOR catalyst comprises an iron-based alloy comprising one or more selected from chromium (Cr), nickel (Ni), carbon (C), manganese (Mn), and optionally molybdenum (Mo).

[0038] In some embodiments, the AOR catalyst comprises an alloy comprising iron, nickel, chromium, and carbon. In some embodiments, iron is present in the AOR catalyst at about 60 wt.% to about 90 wt.% of the AOR catalyst. In some embodiments, nickel is present in the AOR catalyst at about 0.1 wt.% to about 20 wt.%. In some embodiments, chromium is present in the AOR catalyst at about 8 wt.% to about 25 wt.%. In some embodiments, carbon is present in the AOR catalyst at about 0.05 wt.% to about 2.1 wt.%.

[0039] In some embodiments, the AOR catalyst further comprises manganese (Mn) or molybdenum (Mo). In some embodiments, the AOR catalyst further comprises manganese (Mn) and molybdenum (Mo). In some embodiments, Mn is present in the AOR catalyst at about 0.1 wt.% to about 13.0 wt.%. In some embodiments, Mo is present in the AOR catalyst at about 0.1 wt.% to about 3.0 wt.%.

[0040] In some embodiments, a surface of the AOR catalyst is modified to enhance catalytic activity toward ammonia oxidation. In some embodiments, the surface of the AOR catalyst is modified by one or more methods selected from the group consisting of mechanical polishing, sandblasting, plasma treatment, laser etching, electrochemical activation, and chemical etching.

[0041] In some embodiments, the cathodic compartment comprises a cathode and a catholyte. In some embodiments, the cathodic compartment further comprises a hydrogen evolution reaction (HER) catalyst. In some embodiments, the HER catalyst comprises at least one metal selected from a group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), platinum (Pt), palladium (Pd), iridium (Ir), ruthenium (Ru), rhodium (Rh), manganese (Mn), molybdenum (Mo), and gold (Au), or an alloy or a combination thereof. In some embodiments, the HER catalyst comprises a monometallic, a bimetallic, or a trimetallic configuration, which one or more metals are integrated as an alloy, a layered structure, or a core–shell configuration. In someWSGR Docket No.70778-702.601 embodiments, the HER catalyst comprises a nickel alloy comprising one or more metals selected from a group consisting of iron (Fe), ruthenium (Ru), platinum (Pt), molybdenum (Mo), manganese (Mn), cobalt (Co), copper (Cu), and silver (Ag), wherein Ni content ranges from about 30 wt.% to 99 wt.%. In some embodiments, the HER catalyst comprises a platinum-based catalyst comprising Pt supported on carbon (Pt–C). In some embodiments, the HER catalyst comprises platinum (Pt) and at least one or more additional metals selected from a group consisting of nickel (Ni), cobalt (Co), iron (Fe), ruthenium (Ru), palladium (Pd), copper (Cu), and silver (Ag), wherein Pt content ranges from about 10 wt.% to about 90 wt.%.

[0042] In some embodiments, the cathodic compartment comprises an aqueous solution of one or more alkaline hydroxides comprising potassium hydroxide (KOH), sodium hydroxide (NaOH), or lithium hydroxide (LiOH).

[0043] In some embodiments, the method further comprises preventing water crossover, gas mixing, or electrolyte imbalance by a membrane or a separator located in the cathodic compartment. In some embodiments, the cathodic compartment further comprises the catholyte comprising aqueous ammonia with one or more alkaline additives comprising KOH, NaOH, or LiOH. In some embodiments, the cathodic compartment further comprises an acidic aqueous electrolyte comprising hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), phosphoric acid (H₃PO₄), or trifluoromethanesulfonic acid (triflic acid, CF₃SO₃H).

[0044] In some embodiments, the anodic compartment and the cathodic compartment are separated by a separator. In some embodiments, the separator comprises a membrane, porous diaphragm, or a multilayer laminate structure. In some embodiments, the separator comprises a bipolar membrane (BPM). In some embodiments, the separator allows selective ionic transport for protons (H⁺) or ammonium ions (NH₄⁺). In some embodiments, the separator facilitates ionic conduction between the compartments while preventing or minimizing the direct crossover or mixing of the anolyte and the catholyte. In some embodiments, the separator maintains gas-phase separation, allowing for independent evolution and collection of hydrogen at the cathode and nitrogen at the anode without cross-contamination or back-diffusion of reactive species. In some embodiments, the separator comprises one or more of polyethylene, polypropylene, polysulfone, polyamide, polyethersulfone (PES), polyvinylidene fluoride (PVDF), polyester, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), perfluoroethylene-propylene (FEP), ethylene-tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene- chlorotrifluoroethylene (ECTFE), or polybenzimidazole (PBI). In some embodiments, the separator is fabricated into a porous, a non-porous, or a reinforced membrane structure. In some embodiments, the separator comprises one or more of sulfonated polystyrene, sulfonatedWSGR Docket No.70778-702.601 polyether ether ketone (sPEEK), sulfonated polyarylether ketone (sPAEK), sulfonated polybenzimidazole (sPBI), sulfonated polysulfone, sulfonated polyetherimide, sulfonated polyetherketone, or sulfonated polyphosphazene. In some embodiments, the separator comprises one or more materials selected from the group consisting of poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), or Nafion®. In some embodiments, the separator comprises a ceramic membrane, a glass fiber filter, a porous insulating body, or a chemically stable polymer blend. In some embodiments, the porous insulating body comprises or is filled with agar, zeolite, or metal oxides. In some embodiments, the separator comprise a hydrophilic porous membrane or diaphragm configured to facilitate ionic conductivity. In some embodiments, the separator comprises a porous membrane comprising Zirfon® UPT or a polysulfone-based membrane reinforced with zirconia particles.

[0045] In some embodiments, the method further comprises increasing an ionic conductivity of liquefied ammonia using one or more additives in the ammonia preparation unit. In some embodiments, the one or more additives are selected from a group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), propanol (C₃H₇OH), butanol (C4H10O), dimethyl sulfoxide (C₂H₆OS), glycerol (C₃H₈O₃), acetic acid (CH₃COOH), dimethylformamide (C₃H₇NO), pyridine (C₅H₅N), ethylene glycol (C₂H₆O₂), methanol (CH₃OH), acetone (C₃H₆O), tetrahydrofuran (C₄H₈O), diethylamine (C₄H₁₁N), triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), acetonitrile (C2H3N), N- methyl-2-pyrrolidinone (C5H9NO), hexamethylphosphorous triamide (C6H19N3OP), nitromethane (CH3NO2), urea (CH4N2O), phenol (C6H6O), 2-pyrrolidone (C4H7NO), diisopropylamine (C6H15N), 1,4-dioxane (C4H8O2), and morpholine (C4H9NO). In some embodiments, the one or more additives are selected from a group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), glycerol (C₃H₈O₃) or triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), and ethylene glycol ((CH₂OH)₂). In some embodiments, the one or more additives are configured to function as a supporting electrolyte. In some embodiments, the one or more additives are selected from group comprises 1,3,5-trinitrobenzene (C₆H₃(NO₂)₃), 2,4,6-trinitroaniline (C₆H₂(NO₂)₃NH₂), tetranitromethane (C(NO₂)₄), sodium nitromethanide (CH₂NO₂Na), ammonium nitroethane (CH₃CH₂NO₂NH₄), , nitroguanidine (CH₄N₄O₂), methyl nitramine (CH₃N₂O₂), sulfanilamide (C₆H₈N₂O₂S), cyanamide (CH₂N₂), phthalimide (C₆H₄(CO)₂NH), thiourea (CS(NH₂)₂), thiosemicarbazide (H₂NNHC(S)NH₂), benzamide (C₆H₅CONH₂), phenylacetamide (C₆H₅CH₂CONH₂), cyanocetamide (CH₂(CN)CONH₂), ethylamine hydrochloride (C₂H₅NH₂·HCl), and diethylamine ((C₂H₅)₂NH). In some embodiments, the one or moreWSGR Docket No.70778-702.601 additives remain inert with both the cathodic and anodic compartment. In some embodiments, the one or more additives modify the vapor pressure of ammonia by about 5% to about 40% when in contact with ammonia. In some embodiments, the one or more additives modify the ionic conductivity of liquefied ammonia by about 2 to about 100 times when in contact with ammonia.

[0046] In some embodiments, the method further comprises removing moisture from ammonia feedstock prior to introduction into the ammonia conditioning unit using a dryer. In some embodiments, the method further comprises isolating product gases and recovering unreacted ammonia using one or more downstream gas management units placed in the electrochemical cell. In some embodiments, the one or more downstream gas management units comprise gas– liquid separation modules, ammonia-selective adsorbent units, and gas purification components for hydrogen and nitrogen, or tailored to the specific operating configuration (e.g., flow-through or non-flow).

[0047] In some embodiments, the method further comprises utilizing one or more compounds of formula AnQm as an adsorbent medium. In some embodiments, the adsorbent medium comprises one or more compositions comprising at least one of lithium thiocyanate (LiSCN), ammonium thiocyanate (NH₄SCN), or sulfamide (NH₂SO₂NH₂). In some embodiments, the electrochemical cell is configured for continuous-flow or batch operation. In some embodiments, the electrochemical cell further comprises a sealing gasket, an electrical terminal, a flow port, a thermal regulation component, or a pressure or flow control element.

[0048] In some embodiments, the method further comprises purifying the hydrogen using a downstream gas separation unit.

[0049] In some embodiments, the method further comprises isolating the nitrogen and the ammonia from liquid phase using a gas–liquid separator that is positioned downstream of the anode outlet. In some embodiments, the method further comprises selectively capturing residual ammonia using a second adsorbent unit. In some embodiments, the method further comprises recovering ammonia and isolating the hydrogen and nitrogen using a downstream gas–liquid separation and a multi-stage adsorbent-based purification.

[0050] Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in this art from the following detailed description, wherein only illustrative embodiments of the present disclosure are shown and described. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed. As will be realized, the present disclosure is capable of other and different embodiments, and its several details are capable of modifications in various obviousWSGR Docket No.70778-702.601 respects, all without departing from the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. INCORPORATION BY REFERENCE

[0051] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and / or take precedence over any such contradictory material. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present disclosure will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the disclosure are utilized, and the accompanying drawings (also “Figure” and “FIG.” herein), of which:

[0053] FIG.1 depicts a schematic of an ammonia electrolysis system, in accordance with aspects of the present disclosure.

[0054] FIG.2 depicts a schematic of an ammonia electrolysis system including anodic and cathodic compartments and a separated electrochemical cell, in accordance with aspects of the present disclosure.

[0055] FIG.3 depicts a schematic of a continuous-flow ammonia electrolysis system with a regenerative liquid loop, in accordance with aspects of the present disclosure.

[0056] FIG.4 depicts a schematic of an ammonia electrolysis system incorporating additional elements to the apparatus of FIG.3.

[0057] FIG.5 depicts an assembled ammonia electrolysis system constructed in accordance with aspects of the present disclosure.

[0058] FIG.6 depicts a workflow of an ammonia electrolysis process in accordance with aspects of the present disclosure.

[0059] FIG.7 depicts a bar graph showing the ionic conductivity of various liquefied ammonia compositions (LAC), where each LAC sample represents a liquefied ammonia composition produced using one or more AnQm-type compounds, in accordance with aspects of the present disclosure.

[0060] FIG.8 depicts a bar graph showing the dynamic viscosity of various liquefied ammoniaWSGR Docket No.70778-702.601 compositions (LAC), where each LAC sample represents a liquefied ammonia composition produced using one or more AnQm-type compounds, in accordance with aspects of the present disclosure.

[0061] FIG.9A depicts a current–voltage (I–V) curve illustrating the electrochemical performance of an ammonia electrolysis system configured according to Example 1, utilizing a noble-metal-based anodic catalyst for the conversion of ammonia to hydrogen and nitrogen.

[0062] FIG.9B depicts a current–voltage (I–V) curve showing the performance of the ammonia electrolysis system described in Example 3, using a noble-metal-free iron-based alloy catalyst for ammonia splitting.

[0063] FIG.10 depicts a current–voltage (I–V) curve showing the electrochemical performance of the ammonia electrolysis system described in Example 7, in which a liquefied ammonia anolyte and an acidic catholyte—each containing one or more catalysts as described herein—are separated by an ionic exchange membrane.

[0064] FIG.11 depicts the vapor pressure of ammonia as a function of temperature for both pure ammonia and the various liquefied ammonia compositions (LAC), where each LAC sample represents a liquefied ammonia composition produced using one or more AnQm-type compounds, as described in this disclosure described herein. The figure also indicates the corresponding temperature–pressure ranges over which each remains in the liquid phase, in accordance with aspects of the present disclosure. DETAILED DESCRIPTION

[0065] Ammonia (NH₃) has gained significant attention as a carbon-free hydrogen carrier due to its high energy density, established storage and distribution infrastructure, and its ability to decompose without generating carbon emissions. However, conventional methods for converting ammonia into hydrogen, such as thermal cacking or electrolysis often require high temperatures and pressures, suffer from poor solubility and conductivity of electrolytes in liquid ammonia, and exhibit degradation of electrochemical components in ammonia-rich environments, leading to those methods being dangerous, expensive, and inefficient. The systems and methods provided herein allow for the electrochemical conversion of ammonia into hydrogen and nitrogen gases under mild operating conditions, including ambient temperature and pressure, making those systems and methods safe and efficient, thereby addressing the key limitations associated with conventional approaches.

[0066] As noted above, ammonia (NH₃) has emerged as a promising carbon-free hydrogen carrier due to its high energy density, well-established storage and distribution infrastructure, andWSGR Docket No.70778-702.601 the absence of carbon emissions upon decomposition. It is increasingly being considered as a means to transport hydrogen from production sites to end-use locations where hydrogen infrastructure is limited or under development. While significant progress has been made in the production, storage, and transportation of ammonia, the efficient conversion of ammonia back into hydrogen at the point of use remains a major technical challenge. Conventional thermal cracking of ammonia, which decomposes NH₃ into hydrogen and nitrogen at elevated temperatures (typically 600–1000^°C) and high pressures (30–50^bar), has only limited commercial implementation due to the high energy requirements, complicated downstream process for H2and N2separation, emission of NO^ species, slow system dynamics, and associated capital and operational expenditures.

[0067] Electrochemical cracking (E-Cracking) approaches, such as ammonia electrolysis, offer a potential alternative for converting ammonia into hydrogen and nitrogen under milder conditions. Electrolysis enables modularity, on-demand operation, and compatibility with renewable electricity sources. However, current electrochemical systems face significant limitations depending on the form in which ammonia is supplied.

[0068] Additionally, aqueous ammonia solutions may be used in aqueous systems, but in those systems, water competes with ammonia as a reactant, often leading to parasitic reactions, unwanted by-products, and electrode surface poisoning. These effects reduce faradaic efficiency, durability, and limit practical implementation. Moreover, the electrochemical oxidation of ammonia in water can lead to the formation of nitrate and nitrite species, which are undesirable in clean hydrogen production. Alternative systems using ammonia dissolved in organic solvents also present challenges, such limited ammonia solubility, low ionic conductivity, environmental concerns, and the potential formation of carbon-based side products, particularly when carbon- containing solvents are used in oxidative environments.

[0069] Alternatively, direct electrolysis of liquid ammonia offers a pathway to eliminate the competing influence of water and carbon-containing solvents. However, liquid ammonia presents several critical challenges for electrochemical applications. Liquid ammonia exhibits intrinsically low ionic conductivity (∼10⁻⁴ mS / cm), and its poor solvent properties limit the dissolution and dissociation of supporting electrolytes, making it difficult to achieve sufficient ionic transport. In addition, suitable catalysts and separator materials are limited, as many conventional electrolysis components degrade or lose functionality in liquid ammonia environments. Furthermore, conventional systems that use liquid ammonia typically require either high-pressure containment or cryogenic refrigeration to maintain ammonia in the liquid state, increasing system complexity and cost. These factors have hindered the practical application of liquid ammonia electrolysis forWSGR Docket No.70778-702.601 hydrogen production.

[0070] Accordingly, the currently used conventional methods of ammonia electrolysis all present significant drawbacks, such as requiring significant amounts of necessary resources and inefficiency.

[0071] The compositions, systems, and methods described herein enable the electrochemical conversion (E-Cracking) of ammonia into hydrogen and nitrogen gases under mild operating conditions, such as ambient temperature and pressure. This approach addresses key limitations of conventional ammonia cracking and electrolysis systems, including the need for high temperatures and pressures, poor electrolyte solubility and conductivity in liquid ammonia, and degradation of conventional electrochemical components in ammonia-rich environments. The disclosed system employs an ammonia liquefaction composition that functions both as an ammonia carrier and as an electrolyte, thereby eliminating the need for high-pressure containment or cryogenic refrigeration. The electrolysis is then carried out in a solvent-free environment—without added water or organic solvents—which minimizes or eliminates the formation of nitrogen oxide (NO^) species, particularly at the anode. The disclosed system enables preparation of ammonia in a liquid or gel phase with an ammonia liquefier (e.g., as a liquefied-ammonia composition) at broader range of temperature and pressure compared to the neat ammonia (such as at ambient conditions) such that the liquefied-ammonia composition can be delivered to the electrolyzer for conversion into hydrogen.

[0072] Electrochemical cells used in the systems and methods may also include anodic and cathodic compartments equipped with electrode materials that serve as catalysts for ammonia oxidation and hydrogen evolution, respectively, increasing effectiveness and efficiency. These may include metallic, alloyed, or carbon-based catalytic surfaces capable of operating effectively in liquefied ammonia. A membrane-based separator may also be employed to enable in situ gas separation, allowing hydrogen and nitrogen to be independently recovered from within the electrochemical cell. The overall system architecture may include one or more of an ammonia liquefaction unit, an electrochemical cell comprising anodic and cathodic compartments with catalytic electrodes, an optional membrane separator, and downstream gas separation and purification units, enabling safe, scalable, and efficient hydrogen production from ammonia.

[0073] While various embodiments of the invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions may occur to those skilled in the art without departing from the invention. Various alternatives to the embodiments of the invention described herein may be employed.WSGR Docket No.70778-702.601 DEFINITIONS

[0074] “A,” “an” and “the” include plural references unless the context clearly dictates, thus the indefinite articles “a”, “an,”, and “the” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[0075] The term “about” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±5%, ±1%, or ±0.1% from the specified value, as such variations are appropriate to perform the disclosed methods or in connection with a disclosed composition. Whenever the term “about” precedes the first numerical value in a series of two or more numerical values, the term “about” applies to each of the numerical values in that series of numerical values. For example, about 1, 2, or 3 is equivalent to about 1, about 2, or about 3.

[0076] The term “atm” as used herein refers to 1 atmospheric pressure.

[0077] As used herein, “multi-atomic moiety” means a multi-atomic moiety comprising at least two atoms. In some embodiments, the multi-atomic moiety comprises a multi-atomic moiety with at least two atoms, wherein there are at least one atom from Groups 15, 16, or 17 in the Periodic Table of Elements or a combination thereof. As part of the (AnQm)(NH3)x, the atoms may be capable of forming noncovalent bonds with ammonia. In some embodiments, a multi-atomic group contains at least one atom from boron (B), Group 15, or Group 16 of periods 3, 4, 5, and 6, or a combination thereof,

[0078] Groups 15, 16, or 17 refer to those corresponding groups in the Periodic Table of Elements.

[0079] The term “ambient conditions” is defined herein to encompass a range of environmental parameters tailored for both general and specific commercial applications. Broadly, ambient conditions are characterized by temperatures ranging from about 10 °C to 30 °C and atmospheric pressures between 0.75 atm and 1.25 atm. This definition allows for flexibility to accommodate variations across diverse geographic and seasonal environments. In some embodiments, ambient conditions refer to temperatures between 20 °C and 30 °C, with pressures around 1 atm. In addition, the term “near-ambient conditions” as used herein refers to a temperature of 10-40 °C and a pressure of 0.8-1.2 atm.

[0080] As used herein, the “liquefier material” or “ammonia liquefier” or “ammonia liquefier composition” or “liquefier” may comprise a single compound or multiple compounds having the formula AnQmor (AnQm)(NH3)x, wherein x is 1 to 8 (e.g., in one embodiment, a liquefier material may comprise NH4SCN, while in another embodiment, the liquefier material may comprise both NH4SCN and sulfamide). While embodiments with one or two compounds are listed here, theseWSGR Docket No.70778-702.601 are exemplary, and more than one or two compounds having the formula AnQmor (AnQm)(NH3)xmay be present in the liquefier material. Similarly, the liquefier material when adsorbed ammonia may comprise a single compound or multiple compounds having the formula (AnQm)(NH3)y, wherein y is a number that is at least 1 and is larger than x. The liquefier material is configured to adsorb gaseous or liquid ammonia molecules converting ammonia to liquefied ammonia products when interacting with the ammonia under controlled conditions of temperature and pressure.

[0081] As used herein, the term “ammonia liquefied product(s)” may also be referred to “liquefied ammonia composition(s)” (e.g., the liquefier material when absorbing ammonia and stabilized it in liquid state) refer to compounds / complexes with the general formula (AnQm)(NH3)y, wherein y is a number that is at least 1 and larger than x as described herein. As described herein, the combination of liquefier material and ammonia (e.g., which forms the liquefied ammonia products) allow for maintaining ammonia in liquid form at broad conditions (e.g., a broad range of temperature and pressure, such as ambient pressure and temperature) than would be required for pure ammonia. The liquefied ammonia products may include one or more ammonia liquefier compositions and may further comprise one or more additives as described herein.

[0082] As used herein, the terms “liquefied” or “liquefication” mean that about 1% to about 100% of the ammonia product is in liquid phase. Preferably about 10% to about 90% of the ammonia product is in liquid phase. It is especially preferred that about 20% to about 80% of the ammonia product is in liquid phase.

[0083] Generally, as referred to herein, “Ammonia feed stream.” refers to a stream comprising anhydrous ammonia (NH₃) supplied in conventional industrial form, typically having a purity of at least about 98 wt.% (e.g., about 98–99.99 wt.%), unless otherwise specified. The stated range is non-limiting and encompasses any commercially available ammonia purity. The ammonia feed stream may be provided in traditional pressurized or refrigerated form. In certain embodiments, the stream may include minor impurities (e.g., water or inert gases) consistent with the indicated purity.

[0084] Whenever the term “at least,” “greater than,” or “greater than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “at least,” “greater than” or “greater than or equal to” applies to each of the numerical values in that series of numerical values. For example, greater than or equal to 1, 2, or 3 is equivalent to greater than or equal to 1, greater than or equal to 2, or greater than or equal to 3.

[0085] As used herein, “electrochemical efficiency” or “Faradaic efficiency (FE)” or “System Efficiency” is defined as the fraction of electrical charge that forms the specified target product H₂ and / or N₂ from ammonia, reported as a percentage; FE (%) = (Charge attributed to H₂ and / orWSGR Docket No.70778-702.601 N₂) / (Total charge passed) × 100.×100 Where the charge attributable to formation of the product (H₂ or N₂), determined experimentally by measuring the product output (e.g., gas analyzer), converting the measured amount to moles, and calculating the theoretical charge required by its overall stoichiometry (electrons-per-mole of H₂ or N₂ × Faraday’s constant). The Qtotalis the total charge passed over the same interval, obtained by integrating current over time. FE may be reported separately as FEH2 and FEN2 , and / or in aggregate as the ratio of (QH2+QN2) to Qtotalat a stated operating point.

[0086] Whenever the term “at most,” “no more than,” “less than,” or “less than or equal to” precedes the first numerical value in a series of two or more numerical values, the term “at most,” “no more than,” “less than,” or “less than or equal to” applies to each of the numerical values in that series of numerical values. For example, less than or equal to 3, 2, or 1 is equivalent to less than or equal to 3, less than or equal to 2, or less than or equal to 1.

[0087] In this disclosure, the terms "comprising", "having", and "including" are intended to be inclusive or open-ended, meaning they do not exclude additional elements or steps not explicitly mentioned. Throughout the specification, when a portion is described as "including," "containing" or "having" an element, it is to be understood that additional elements may also be present, unless explicitly stated otherwise, and the presence of such additional elements is not excluded.

[0088] The phrase "or combinations thereof" refers to all possible permutations and combinations of the items listed before it. For instance, "A, B, C, or combinations thereof" is intended to cover A, B, C, AB, AC, BC, or ABC, as well as at least one of BA, CA, CB, CBA, BCA, ACB, BAC, or CAB, depending on the context where the sequence matters. Additionally, "A, B, C, or combinations thereof" may encompass combinations with repetitions of one or more items or terms, such as BB, AAA, MB, BBC, AAABCCCC, CBBAAA, CABABB, and similar. Those skilled in the art will recognize that there is generally no restriction on the number of items or terms in any combination unless context explicitly dictates otherwise. In the following sections, specific embodiments of this disclosure will be described in detail with reference to the drawings. However, it should be understood that the disclosure is not limited to these particular embodiments.

[0089] The terms "first," "second," and similar descriptors are used solely to distinguish one element from another and should not be interpreted as implying any limitation on the elements.WSGR Docket No.70778-702.601 SYSTEM

[0090] In one aspect, and with reference to FIG.1, the present disclosure provides an ammonia electrolysis system 100 configured for the electrochemical conversion of ammonia into hydrogen and nitrogen gases. The system 100 may comprise: an ammonia source unit configured to supply ammonia feedstock (e.g., as ammonia feedstock stream 102); an ammonia preparation unit 104 (also referred to herein as an “ammonia conditioning unit”) comprising a liquefaction module that utilizes a liquefier comprising one or more compounds of formula AnQm to convert the feedstock ammonia (e.g., of ammonia feedstock stream 102) into a liquefied form under a wide range of operating conditions, including ambient temperature and pressure; optionally one or more supporting electrolytes; and an electrochemical cell configured to receive the liquefied ammonia and convert it into hydrogen and nitrogen via electrochemical oxidation and reduction reactions. In this depicted example, a power supply 110 is operatively connected to the electrodes of the electrochemical cell 108 to provide the potential required to drive the electrochemical conversion process.

[0091] The system 100 may enable the electrochemical conversion of ammonia into hydrogen and nitrogen gases under mild operating conditions. The system 100 employs a liquefied ammonia composition that functions both as an ammonia carrier and as an electrolyte, thereby eliminating the need for high temperatures and pressures. The electrolysis is then carried out in a solvent-free environment—without added water or organic solvents—which minimizes or eliminates the formation of nitrogen oxide (NO^) species, particularly at the anode.

[0092] In some embodiments, the ammonia feedstock stream 102 (also referred to herein as “ammonia feedstock 102”) may comprise ammonia (either in gaseous or liquid form). The ammonia feedstock 102 may include liquefied ammonia. Additionally, the liquefier liquefies ammonia upon contact with the liquefier (e.g., by creating a complex with ammonia which is in liquid state at broader range of temperature and pressure compared to the pure ammonia.) In some embodiments, the liquefier may keep the ammonia in a liquid state at ambient temperature and pressure, allowing the ammonia to be stored more safely and efficiently when compared to conventional methods. In some embodiments, the liquefier may keep ammonia in a liquid phase suitable for electrolysis and improve the ionic conductivity of the medium for electrolysis.

[0093] In some embodiments, and with reference to FIG.2, the present disclosure provides an ammonia electrolysis system 200 comprising: an ammonia source unit configured to supply ammonia feedstock 202; an ammonia preparation unit 204 comprising a liquefaction module that utilizes a liquefier (also referred to herein as “ammonia liquefier compositions”) comprising one or more compounds of formula AnQm , and optionally one or more additives, to generate aWSGR Docket No.70778-702.601 liquefied ammonia stream 206 that is stable in liquid or gel form at near-ambient conditions. In some embodiments, ambient conditions include a pressure between 0.75 atm and 1.25 atm and / or a temperature ranging from about 10 °C to 30 °C. In this depicted example, the liquefied ammonia stream 206 is provided to an electrochemical cell 208, which is connected to a power supply 210. In some embodiments, the electrochemical cell 208 comprises an anodic compartment and a cathodic compartment, which may be separated by a membrane or a porous separator configured to allow selective ionic transport. The electrochemical cell 208 may further include one or more electrolytes (also referred to herein as a “supporting electrolyte”,) which enhances ionic conductivity prior to delivery to the electrochemical cell. In this depicted example, power supply 210 is operatively connected to the electrodes disposed within the anodic and cathodic compartments, respectively, and is configured to apply a sufficient voltage to drive ammonia oxidation at the anode and hydrogen evolution at the cathode. In other embodiments, power supply 210 may not be operatively connected to the electrodes. The liquefier is configured to stabilize ammonia in a liquid state upon contact with ammonia, thereby forming a complex of the formula, (AnQm)(NH3)y, wherein y is a number ranging from 1 to 8.

[0094] In some embodiments, the ammonia electrolysis system 200 includes an ammonia preparation unit configured to supply conditioned (e.g., liquefied) ammonia to both the anodic and cathodic compartments of the electrochemical cell. The liquefied ammonia delivered to the anodic and cathodic compartments of electrochemical cell 208 may be delivered with the liquefier (e.g., in a complex with the liquefier). In those embodiments, the liquefier may also act as an electrolyte in the anodic and cathodic compartments. The ammonia preparation 204 unit may generate a unified liquefied ammonia composition comprising one compound of the formula AnQm, with optional one or more additives, that is compatible with both the anodic and cathodic compartments, which may be split and directed into the two compartments. This configuration may be employed where a unified feed composition is suitable for both ammonia oxidation reaction (AOR) and hydrogen evolution reactions (HER), or where system simplicity and cost minimization are desired. In some embodiments, the feedlines may be independently regulated to control flow rates or pressures to the respective compartments. Independent regulation may be advantageous to provide finer control of anodic and cathodic operating conditions, or in embodiments where different liquefied-ammonia compositions are delivered to the two compartments depending on compatibility with the respective half-reactions.

[0095] In some embodiments, the system comprises two distinct ammonia preparation units, each operatively connected to one of the anodic or cathodic compartments. The anodic compartment may be configured to generate a formulation optimized for ammonia oxidationWSGR Docket No.70778-702.601 (e.g., promoting electron transfer and minimizing side reactions), while the cathodic compartment may generate a formulation tailored for efficient hydrogen evolution (e.g., enabling higher proton availability or ionic conductivity).

[0096] The anodic half-reaction occurring within the anodic compartment may be represented by Reaction Formula I, in which ammonia (NH₃) is oxidized to produce nitrogen gas (N₂), ammonium ions ([NH₄]⁺), and electrons (e⁻): 8 NH3 → N2 + 6 [NH4]+ + 6 e– (Reaction Formula I)

[0097] The cathodic half-reaction corresponds to the hydrogen evolution reaction (HER), wherein hydrogen ions (H⁺) and / or ammonium ions ([NH₄]⁺) are electrochemically reduced to generate hydrogen gas. In certain embodiments, the HER may proceed via the following reaction pathway: 6[NH₄]⁺ + 6 e⁻ → 3 H₂ + 6 NH₃ (Reaction Formula II)

[0098] When combined the anodic ammonia oxidation and the cathodic hydrogen evolution reaction, the overall net reaction of the system may be summarized as: 2NH₃ → N₂ + 3 H₂ (Reaction Formula III)

[0099] The use of distinct liquefaction compositions for each compartment allows fine-tuned control of the local electrochemical environment, which may enhance reaction efficiency, selectivity, or system durability. In some embodiments, the preparation units may utilize different temperatures, additives, or chemical complexes based on the compartment-specific requirements.

[0100] In some embodiments, and with reference for FIG.3, the ammonia electrolysis system 300 is further configured for continuous flow operation with a regenerative liquid loop. In this depicted example, ammonia feedstock 302 is provided to ammonia preparation unit 304 to generate a prepared ammonia stream 306 (e.g., similarly to liquefied ammonia streams 104 and 204 of FIGs.1 and 2, respectively). The prepared ammonia stream 306 may comprise a liquefied ammonia composition(s)(e.g., having the formula (AnQm)(NH3)y,), and optional one or more additives, which is directed into one or both of the anodic and cathodic compartments of the electrochemical cell. In some embodiments, the ammonia stream 306 may further comprise one or more supporting electrolytes. Following the electrochemical reaction comprising conversion of liquefied ammonia into hydrogen and nitrogen via electrochemical oxidation and reduction reactions in the electrochemical cell 308, the liquid effluent of the electrochemical cell 308—nowWSGR Docket No.70778-702.601 depleted of a portion of its ammonia content but still containing the carrier components—is transferred to a gas-liquid separation unit 312. The gas-liquid separation unit is configured to extract the evolved hydrogen and nitrogen gases while allowing the remaining liquid phase to be recovered (e.g., from streams 314 and 316, which may contain liquid and / or gas that is removed from electrochemical cell 308). In this depicted embodiment, the liquid is then directed back to the ammonia preparation unit 304 as streams 318 and 320, where it is re-saturated with ammonia to restore its original composition and functionality. This regenerated liquid is then reintroduced into the electrochemical cell, enabling sustained operation over extended cycles without accumulation of solid byproducts or loss of carrier media. In some embodiments, the system may include flow controllers, pressure regulators, and thermal management elements to optimize the efficiency and consistency of each cycle. In some embodiments, the liquid (e.g., as streams 318 as 320) may not be directed back to be re-saturated with ammonia, and may be directed to another location.

[0101] In some embodiments, and with reference to FIG.4, the system includes multiple ammonia preparation and recirculation units for the anodic and cathodic compartments, respectively. For example, in this depicted example, system 400 includes both ammonia conditioning unit 404a and ammonia conditioning unit 404b. In this depicted example, each of ammonia conditioning unit 404a and ammonia conditioning unit 404b is supplied by an independent flow loop comprising its own ammonia preparation unit (e.g. ammonia preparation units 404a and 404b), recirculation pump, and gas-liquid separation stage (e.g., including liquid / gas separator 412a and 412b). For example, ammonia conditioning unit receives ammonia (e.g., of ammonia feedstock 402) and prepares liquefied ammonia stream 406 (e.g., by contacting liquefier as described herein with the ammonia), which is then provided to electrochemical cell 408 at its (cathodic / anodic) compartment. This configuration allows the formulation of the carrier fluid to be independently optimized for the chemistry of each compartment—for example, the anodic loop (e.g., including streams 416 and liquid / gas separator 412b) may include additives that promote ammonia oxidation and nitrogen selectivity, while the cathodic loop (e.g., including streams 414 and liquid / gas separator 412a) may favor enhanced proton or ammonium transport and hydrogen evolution. Independent control of flow rate, temperature, and ammonia saturation enables fine-tuning of electrochemical performance and improves long-term system stability. Optionally, the loops may include temperature management modules such as inline heat exchangers to counteract the exothermic nature of ammonia absorption during reconditioning. While certain configurations are shown in FIG.4, these are exemplary, and other configurations (e.g., by including or removing one or more streams, separators, or ammonia conditioning units)WSGR Docket No.70778-702.601 may be used.

[0102] In some embodiments, with reference to FIG.4 and FIG.5, the system includes one or more adsorbent units positioned downstream of the gas-liquid separation units 412a and 412b. Each adsorbent unit is configured to remove residual or unreacted ammonia vapor from the separated gas streams—specifically, hydrogen and nitrogen—prior to final collection or use. In certain configurations, a first adsorbent unit 422a may be connected to the cathodic gas stream 418 and configured to remove ammonia from the hydrogen output, while a second adsorbent unit 422b may be connected to the anodic gas stream 420 to purify the nitrogen product. The adsorbent material may comprise metal salts, acidic porous solids, zeolites, activated carbon, ion- exchange resins, or other ammonia-specific sorbents. This additional purification stage ensures that the product gases meet application-specific purity requirements and prevent cross- contamination in downstream hydrogen or nitrogen utilization systems.

[0103] In some embodiments, the adsorbent unit 422a and 422b may comprise the same liquefiers as described herein used within the ammonia preparation unit. In this configuration, the adsorbent functions not only to remove unreacted ammonia from the separated gas stream, but also to convert the unreacted ammonia into a liquefied or absorbed form, thereby enabling direct reuse of the unreacted ammonia within the system. In other embodiments, the unreacted ammonia is provided to another unit as a stream, where the unreacted ammonia may be converted into a liquefied or absorbed form using the liquefier (e.g., thus creating the liquefied ammonia composition). The recovered liquefied ammonia (e.g., within the resulting liquefied ammonia composition) may be routed back into an ammonia preparation unit (e.g., ammonia preparation unit 404a or 404b) to be re-saturated and blended with the recirculated carrier fluid, or directly delivered to the electrochemical compartments, depending on system architecture. This approach allows for effective ammonia vapor capture, reduction of chemical losses, and closed-loop operation without requiring separate sorbents or external ammonia recovery infrastructure. In cases where the same AnQmformulation is used for both the adsorbent and the electrolyte carrier, the process enables seamless reintegration of recovered ammonia into the electrolysis cycle.

[0104] In some embodiments, the ammonia electrolysis system 400 may include a dryer configured to remove moisture from ammonia gas prior to introduction of ammonia gas into the ammonia preparation unit. In certain embodiments, the system may additionally include a moisture removal unit positioned downstream of the ammonia preparation unit configured to remove possible moisture content in the liquefied ammonia.

[0105] In some embodiments, one of more of the ammonia electrolysis systems, 100, 200, 300, and 400 of FIGs.1-4 may further comprise one or more auxiliary components selected from:WSGR Docket No.70778-702.601 flow controllers, pressure regulators, heat exchangers, temperature sensors, recirculation pumps, back-pressure valves, gas storage tanks, and integrated safety systems. These components may be operatively connected to the ammonia preparation unit, the electrochemical cell, or the gas-liquid separation units, and may be used to control operational parameters such as temperature, pressure, concentration, or flow rate. In some embodiments, the system is configured as a modular unit or an electrolysis stack comprising multiple repeating electrochemical cells, optionally connected in series or parallel to adjust capacity, redundancy, or scale. In other embodiments, a separate ammonia-conditioned storage unit may be included downstream of the preparation unit to buffer or stabilize the liquefied ammonia prior to delivery to the electrochemical cell. These and other system architectures may be used without departing from the scope of the present disclosure, and the specific layout and component selection may be adapted to accommodate different scales, feedstocks, or application-specific requirements.

[0106] In some embodiments, the system may further comprise one or more hydrogen utilization units operatively connected to the hydrogen outlet of the gas separation or purification system. The hydrogen utilization unit may include a hydrogen fuel cell configured to convert the produced hydrogen into electricity, or an internal combustion engine (ICE) adapted to use hydrogen as a fuel to generate mechanical or electrical power. This configuration may be used in mobile, remote, or off-grid applications where on-site electricity generation is required and external power sources are unavailable or unreliable. In certain embodiments, a portion of the electricity generated by the hydrogen fuel cell may be routed back to power system components such as pumps, sensors, or the electrochemical cell itself, enabling partial or full energy self- sufficiency. In alternate embodiments, the hydrogen may be directed to chemical processing units, hydrogenation systems, or storage tanks depending on application-specific requirements. METHOD

[0107] In one aspect, the present disclosure provides a method for producing hydrogen and nitrogen gases from ammonia via electrochemical conversion. In some embodiments, with reference to FIG.6, the method comprises: (i) supplying ammonia feedstock to an ammonia preparation unit (602); (ii) preparing the ammonia by contacting the ammonia with an ammonia liquefier comprising one or more compounds of formula AnQmto form a liquefied ammonia stream (e.g., of the liquefied ammonia composition) comprising one or more complexes of the formula (AnQm)(NH3)y, wherein y is a number ranging from 1 to 8 (604); (iii) delivering the liquefied ammonia to an electrochemical cell comprising an anodic compartment and a cathodic compartment, which may be separated by a membrane or porous separator (606); (v) applying anWSGR Docket No.70778-702.601 electric potential across the electrodes to oxidize ammonia at the anode and reduce protons or ammonium ions at the cathode (608); and (vi) collecting the evolved hydrogen and nitrogen gases (610). In some embodiments, the method may further comprise recovering remaining liquid phase (610) and delivering the remaining liquid phase to the ammonia preparation unit (612). In some embodiments, the method may further comprise treatment and handling of the product gas comprising purifying, venting, compressing, or utilizing the product gases based on application-specific requirements (613). In some embodiments, one or more additives or a supporting electrolyte may be added for preparing the ammonia.

[0108] In some embodiments, there may be a plurality of ammonia preparation units (602). In some embodiments, a first ammonia preparation unit (e.g., ammonia preparation unit 104 of FIG. 1, ammonia preparation unit 204 of FIG.2, ammonia preparation unit 304 of FIG.3, and ammonia preparation unit 404a of FIG.4) receives an ammonia stream (e.g., stream 103 of FIG. 1, stream 203 of FIG.2, stream 303 of FIG.3, and stream 403a of FIG.4) which contacts liquefier within the first ammonia preparation unit. In some embodiments, a second ammonia preparation unit (e.g., ammonia preparation unit 404b of FIG.4) receives a stream of ammonia (e.g., stream 403b of FIG.4).

[0109] In some embodiments, the method comprises liquefying ammonia by contacting the ammonia with a liquefier comprising one or more compounds of the formula AnQm, and optionally one or more additives, to generate a liquefied ammonia stream suitable for electrochemical processing (604). The liquefied ammonia comprises a structure of the formula (AnQm)(NH3)y, wherein y is a number ranging from 1 to 8. The method includes introducing feed ammonia—such as gaseous ammonia, pressurized liquid ammonia, or refrigerated ammonia— into a preparation chamber comprising a liquefier comprising one or more compounds of the formula AnQm under controlled conditions (602). The ammonia interacts with the liquefier to form a liquefied ammonia composition, which may remain in the liquid phase over a wider range of temperatures and pressures, including ambient or near-ambient temperature and pressure conditions. In some embodiments, the ambient conditions may be characterized by temperatures ranging from about 10 °C to 30 °C and atmospheric pressures between 0.75 atm and 1.25 atm. In some embodiments, the liquefier comprises a compound of the general formula AnQm, where A is a first moiety comprising lithium (Li), sodium (Na), hydrogen (H), guanidinium (CH₆N₃⁺), and ammonium (NH₄⁺), or one or more atoms from Group 16 of periods 3, 4, and 5 of the Periodic Table of Elements; and Q is a second moiety comprising at least one atom from boron (B), Group 15, or Group 16 of periods 3, 4, and 5, or a combination thereof. When A is guanidinium (CH₆N₃⁺), Q may also comprise at least one atom from Group 17 of the periodic table. TheWSGR Docket No.70778-702.601 variables n and m represent integers from 1 to 4. The resulting complex of the formula (AnQm)(NH3)y, wherein y is a number ranging from 1 to 8 may be in a liquid or gel, , and may optionally be mixed with a supporting electrolyte prior to delivery to the electrochemical cell. The resulting liquefied ammonia solution may optionally be blended with a supporting electrolyte to enhance ionic conductivity prior to delivery to the electrochemical cell.

[0110] In certain embodiments, AnQmcompositions may include, but not limited to sodium thiocyanate (NaSCN), ammonium thiocyanate (NH₄SCN), sulfamide (SO₂(NH₂)₂), lithium thiocyanate (LiSCN), guanidinium thiocyanate ((CH₆N₃)SCN), and guanidinium trifluoromethanesulfonate (guanidinium triflate). In some embodiment, supporting electrolytes may include, but not limited to ammonium triflate (NH₄OTf), ammonium tetrafluoroborate (NH₄BF₄), ammonium hexafluorophosphate (NH₄PF₆), and sodium triflate (NaOTf), among others. These may be selected based on compatibility with the carrier system, ionic conductivity, thermal stability, or electrochemical potential window.

[0111] In some embodiments, the method comprises circulating a conditioned ammonia stream through the electrochemical cell and regenerating ammonia for repeated use. In some embodiments, the method comprises circulating a conditioned ammonia stream through the electrochemical cell on a continuous basis. The method includes: supplying feed ammonia to an ammonia preparation unit; liquefying the ammonia using a liquefier comprising one or more compounds of formula AnQmunder controlled conditions to generate a liquefied ammonia stream that remains in the liquid phase over a wide range of operating conditions, including ambient or near-ambient temperature and pressure; delivering the conditioned ammonia to the anodic and / or cathodic compartments of an electrochemical cell; and applying a potential across the electrodes to oxidize ammonia at the anode and reduce protons or ammonium ions at the cathode. In some embodiments, the electrochemical cell comprises one or more electrocatalysts to promote ammonia oxidation and hydrogen evolution. The anodic and / or cathodic electrocatalyst may comprise at least one metal selected from nickel, cobalt, iron, copper, chromium, platinum, iridium, ruthenium, rhodium, manganese, or combinations or alloys thereof.

[0112] In some embodiments, the cathodic compartment may contain an aqueous acidic or alkaline solution in place of the liquefied ammonia, enabling hydrogen evolution via proton or water reduction reactions. This approach may reduce cathodic overpotential, improve catalytic efficiency, and enhance gas purity, particularly when combined with well-characterized hydrogen evolution electrocatalysts such as Pt in acidic media or Ni-based alloys in alkaline media. In such configurations, the anodic and cathodic compartments may be separated by a membrane or porous barrier to maintain electrolyte integrity and reaction selectivity.WSGR Docket No.70778-702.601

[0113] The method further includes transferring the effluent from the electrochemical cell to a gas-liquid separation unit to isolate the produced hydrogen and nitrogen gases, and recovering the remaining liquid phase comprising AnQm and optional supporting electrolyte. The recovered liquid may be returned to the ammonia preparation unit, where the recovered liquid may be re- saturated with ammonia to restore its reactive capacity before being recirculated back to the electrochemical cell. In some embodiments, the electrochemical conversion may be performed under ambient or near-ambient operating conditions (e.g., ambient temperature and pressure), made possible by the use of the liquefied ammonia composition, which provides sufficient ionic conductivity and chemical accessibility. The method may further include regulating flow rate, pressure, and temperature within optimal operating ranges to maintain consistent gas evolution and long-term cycling performance.

[0114] In some embodiments, the method further comprises capturing unreacted ammonia vapor (e.g., 418 and 420 of FIG.4) from the product gas stream using one or more ammonia-selective sorbent units (e.g., adsorbent 422a and 422b of FIG.4) positioned downstream of the gas-liquid separation stage. The product gas stream—comprising primarily hydrogen or nitrogen—may contain residual ammonia vapor that is not fully removed during phase separation. To mitigate ammonia loss and improve gas purity, the gas stream may be directed through a vapor recovery unit containing a sorbent material capable of selectively absorbing ammonia.

[0115] The adsorbent material may comprise metal salts, acidic porous solids, zeolites, activated carbon, ion-exchange resins, or other ammonia-specific sorbents. In certain embodiments, the sorbent comprises one or more AnQm compositions of the type used in the ammonia preparation unit, optionally in solid or supported form. Upon contact with the gas stream, the AnQmmaterial absorbs the residual ammonia and converts the residual ammonia into a liquefied or bound form.

[0116] The recovered ammonia may optionally be reintroduced into the ammonia preparation unit or directly into the recirculation loop, depending on system configuration. This step reduces ammonia slip, minimizes environmental release, and improves overall ammonia utilization efficiency. In some embodiments, separate vapor recovery units may be used for the anodic and cathodic gas streams, with tailored flow rates and sorbent capacities to match compartment- specific ammonia crossover behavior.

[0117] In some embodiments, the method further comprises operating the anodic and cathodic compartments of the electrochemical cell using independent flow loops, each configured with its own ammonia preparation unit, recirculation path, and optional gas-liquid separation and vapor recovery systems. In some embodiments, separate feed ammonia streams may be liquefied using distinct AnQm formulations tailored for the chemical environment and reaction requirements ofWSGR Docket No.70778-702.601 the anodic and cathodic compartments, respectively. For example, the anodic loop may include a formulation optimized for efficient ammonia oxidation and nitrogen selectivity, while the cathodic loop may use a composition that enhances proton availability, conductivity, or hydrogen evolution kinetics.

[0118] Each flow loop may be independently regulated in terms of temperature, pressure, ammonia concentration, and flow rate to achieve optimal electrochemical performance. Following electrolysis, the respective effluent streams are processed through compartment- specific gas-liquid separation units, with the remaining liquid phases re-saturated with ammonia and returned to their corresponding compartments. Optional vapor recovery units may be integrated in each loop to capture unreacted ammonia from the hydrogen or nitrogen gas streams. This dual-loop configuration allows for fine-tuned control over each half-cell environment, improving system efficiency, ammonia utilization, and gas purity.

[0119] In some embodiments, each flow loop may be independently regulated at pressures up to about 15 atm. In some embodiments, each flow loop may be independently regulated across pressures in the range of about 0.001 to about 10 atm. In some embodiments, each flow loop may be independently regulated across pressures in the range of about 0.01 to about 5 atm. In some embodiments, each flow loop may be independently regulated at pressures of 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, each flow loop may be independently regulated across pressures of about 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, each flow loop may be independently regulated across pressures of at least 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, each flow loop may be independently regulated across pressures of no more than 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, each flow loop may be independently regulated at temperatures ranging from about -30 °C to about 120 °C. In some embodiments, each flow loop may be independently regulated at temperatures of -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, or 90°C. In some embodiments, each flow loop may be independently regulated at temperatures of about -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, or 90°C. In some embodiments, each flow loop may be independently regulated at temperatures of at least -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 °C. In some embodiments, each flow loop may be independently regulated at temperatures of at most 10, 20, 30, 40, 50, 60, 70, 80 °C.WSGR Docket No.70778-702.601

[0120] Ammonia concentration, which is the molarity of NH₃ in the liquefied ammonia composition (mol of NH₃ per liter of liquid composition) at the applied temperature and pressure. In some embodiments, the ammonia concentration is about 0.05 to about 42 mol / L (M). By way of non-limiting example, the concentration may be about 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, or 42 mol / L. In some embodiments, the ammonia concentration is about 3 to about 42 mol / L, such as about 3, 5, 10, 20, 30, 35, 40, or 42 mol / L.

[0121] In some embodiments, the liquid flow rate is set relative to the electrochemical consumption of ammonia at the selected potential and current density or load, with the setpoint established either (i) theoretically via Faraday’s law for 2 NH₃ → N₂ + 3 H₂ or (ii) empirically from the measured H₂ and / or N₂ production rate at the cathode and / or anode; in either case, the flow is adjusted for utilization and operational practices so that an excess, non-limiting supply of ammonia is maintained at the electrode surface to avoid starvation and preserve ionic conductivity. By way of non-limiting example, the liquefied ammonia feed may be about 10, 20, 50, 75, 100, 150, 200, 300, or 500 mL / min; or about 1, 2, 5, or 10 L / min; or any subrange within about 100 mL / min to about 100 L / min. Equivalently (area-normalized), the flow may for example be about 0.05 to about 5 mL·min⁻¹·cm⁻² (i.e., about 0.5 to about 50 L·min⁻¹·m⁻²), selected according to geometric electrode area, target current density, and FE.

[0122] In some embodiments, the system efficiency (as defined herein) is about 30% to about 99.9%, including any subrange and / or individual value within that range (e.g., about 30%, 40%, 50%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, or 99.9%). In some embodiments, the system efficiency is at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 99%, or at least about 99.9%, measured at a stated operating point (e.g., current density, temperature, and pressure).

[0123] In some embodiments, the method further comprises directing the hydrogen produced by the electrochemical cell to a downstream hydrogen-consuming device. The hydrogen may be supplied to a hydrogen fuel cell configured to convert the chemical energy of hydrogen into electrical energy, or to an internal combustion engine (ICE) adapted to use hydrogen as a fuel. In certain applications, this step enables on-site power generation in remote or off-grid environments, where the electricity produced may be used to power system components, external loads, or storage systems. The nitrogen co-produced may be vented or stored depending on purity requirements and downstream use.WSGR Docket No.70778-702.601 AMMONIA PREPARATION UNIT

[0124] In some aspects, the present disclosure provides an ammonia preparation unit configured to convert gaseous or liquid-phase ammonia into a liquefied form suitable for electrochemical hydrogen production. The preparation process comprises contacting ammonia with a liquefier comprising one or more compounds having the general formula AnQm, wherein the resulting compositions are represented as AnQm(NH₃)yor (AnQm).yNH₃. These compositions exhibit melting points between those of AnQm and pure ammonia, resulting in expanded phase stability over a wider range of temperatures and pressures. The liquefied ammonia AnQm·(NH₃)ytypically exhibits lower vapor pressure and higher boiling or melting points than pure ammonia, enabling storage and handling under ambient or near-ambient conditions. This approach allows ammonia to be used directly as a hydrogen carrier in electrolysis systems without the need for external pressurization, refrigeration, or dissolution in water or solvent media. The resulting liquefied ammonia stream may also provide intrinsic ionic conductivity depending on the composition of AnQm and the ratio of absorbed ammonia, further facilitating direct use as an electrochemical feedstock.

[0125] In some embodiment, the liquefier comprises the compound of the formula denoted as AnQm (referred to as an ammonia liquefier) wherein • A is the first moiety comprising lithium (Li), sodium (Na), hydrogen (H), guanidinium (CH6N3+), and ammonium (NH4+), or one or more atoms from Group 16 of periods 3, 4, and 5 of the Periodic Table of Elements; • Q is a second moiety comprising at least one atom from boron (B), Group 15, or Group 16 of periods 3, 4, and 5, or a combination thereof; • When A is guanidinium (CH6N3+), Q may also comprise at least one atom from Group 17 of the periodic table; and • n is an integer from 1 to 4; m is an integer from 1 to 4.

[0126] In some embodiments, one or more compounds of formula, AnQm, contact with ammonia to produce liquefied ammonia, (AnQm)(NH3)y. In some embodiments, y is the specific amount of ammonia that can be adsorbed which is dependent on the intrinsic structural attributes of the AnQm compound as well as the conditions under which the liquefaction process is conducted. In some embodiments, y may be larger than 0 and smaller than 8. When y is 0, the ammonia liquefier is initially free of ammonia and adsorbs ammonia upon contact with ammonia gas. In some embodiments, the liquefier may initially contain ammonia, with y values less than 8, and subsequently adsorb additional ammonia molecules upon contact with ammonia gas.WSGR Docket No.70778-702.601

[0127] In some embodiments, a single compound disclosed herein may be used for ammonia liquefaction. In some embodiments, one or more compounds disclosed herein may be used for ammonia liquefaction.

[0128] In some embodiments, Q comprises -BF4, -SCN, -SeCN, -NO3, -CF3SO3, -PF6, -ClO4, - C4F9SO3, -CH3CO2, -N(SO2F3)2, -NH2, -N3, or -SbF6.

[0129] In some embodiments, the ammonia liquefier may comprise one or more of compounds selected from a group consisting of NaSCN, HSCN, NH4SCN, NH4SeCN, NaSeCN, (CH6N3)SCN (guanidinium thiocyanate), NH4NO3, NaNO3, (CH6N3)NO3(guanidinium nitrate), LiSCN, LiSeCN, NH4ClO4, NH4BF4, NH4C4F9SO3, (CH6N3)I (guanidinium iodide), (CH6N3)BF4 (guanidinium tetrafluoroborate), NH4CH3CO2, NH4SbF6, , NH4N(SO2F3)2, (CH6N3)PF6(guanidinium hexafluorophosphate), (CH6N3)(CF3SO3) (guanidinium trifluoromethanesulfonate), SO2(NH2)2, I2, SO2(NH2)(NC6H5), and SeO2(NH2)2.

[0130] In some embodiments, the ammonia liquefier comprises NH4SCN, NH4NO3, NaNO3, NaSCN, NH4SCN, LiSCN, or SO2(NH2)2.

[0131] In some embodiment, both cathodic and anodic compartment comprise liquefied ammonia from the same ammonia liquefier.

[0132] In some embodiments, the cathodic and anodic compartment comprise liquefied ammonia from different ammonia liquefiers, depending on the AnQm electrolytic activity.

[0133] An ammonia feedstock stream is received at the preparation unit. The preparation unit contacts the ammonia feedstock stream with the liquefier, thereby forming the liquefied ammonia composition, which is released from the preparation unit in a liquefied ammonia composition stream. That liquefied ammonia composition stream is then provided to both the anodic compartment and the cathodic compartment.

[0134] In some embodiments, the liquefied ammonia on both anodic and cathodic compartments may be produced using SO2(NH2)2.

[0135] In some embodiments, the liquefied ammonia on anodic compartment may be produced using SO2(NH2)2, and liquefied ammonia on cathodic compartment may be produced using NaSCN, NH4SCN, or LiSCN.

[0136] In some embodiments, the liquefied ammonia introduced at the cathodic compartment may be introduced with an ammonia liquefier comprising one or more compounds selected from NaSCN, NH4SCN, SO2(NH2)2, NaNO3, NH4NO3, LiNO3, and LiSCN. In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one is sodium thiocyanate (NaSCN). In some embodiments, the liquefied ammonia introduced at the cathodic compartment mayWSGR Docket No.70778-702.601 comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is SO2(NH2)2. In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is NH4SCN. In some embodiments, the liquefied ammonia introduced at the cathodic compartment comprises NaSCN as the ammonia liquefier. In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is LiSCN. In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is (CH6N3)SCN. In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compounds is NaNO3. In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is NH4NO3. In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is (CH6N3)BF4(guanidinium tetrafluoroborate). In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compounds is (CH6N3)PF6(guanidinium hexafluorophosphate). In some embodiments, the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compounds (CH6N3)I (guanidinium iodide) as the ammonia liquefier. In some embodiments the liquefied ammonia introduced at the cathodic compartment may comprise an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is (CH6N3)CF₃SO₃ (guanidinium triflate).

[0137] In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds selected from sulfamide, NaNO3, NH4NO3, and LiNO3. In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compound, wherein at least one of the compound is NaSCN. In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compounds is SO2(NH2)2. In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compound, wherein at least one of theWSGR Docket No.70778-702.601 compound is NH4SCN. In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compounds is LiSCN. In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is NaNO3. In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compounds is NH4NO3. In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is (CH6N3)BF4 (guanidinium tetrafluoroborate). In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compounds is (CH6N3)PF6 (guanidinium hexafluorophosphate). In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is (CH6N3)I (guanidinium iodide). In some embodiments, liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compound is (CH6N3)SCN (guanidinium thiocyanate). In some embodiments the liquefied ammonia introduced at the anodic compartment may be introduced with an ammonia liquefier comprising one or more compounds, wherein at least one of the compounds is (CH6N3)CF₃SO₃ (guanidinium triflate).

[0138] In some embodiments, the liquefied ammonia compositions described herein remain in liquid form across at pressures up to about 15 atm. In some embodiments, the stabilized liquefied ammonia compositions described herein remain in liquid form across pressures in the range of about 0.001 to about 10 atm. In some embodiments, the liquefied ammonia compositions described herein remain in liquid form across pressures in the range of about 0.01 to about 5 atm. In some embodiments, the liquefied ammonia compositions described herein remain in liquid form at pressures of 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, the liquefied ammonia compositions described herein remain in liquid form across pressures of about 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, the liquefied ammonia compositions described herein remain in liquid form across pressures of at least 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, theWSGR Docket No.70778-702.601 liquefied ammonia compositions described herein remain in liquid form across pressures of no more than 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, the liquefied ammonia compositions described herein remain in liquid form at temperatures ranging from about -30 °C to about 120 °C. In some embodiments, the liquefied ammonia compositions described herein remain in liquid form at temperatures of -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, or 90°C. In some embodiments, the liquefied ammonia compositions described herein remain in liquid form at temperatures of about -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, or 90°C. In some embodiments, the liquefied ammonia compositions described herein remain in liquid form at temperatures of at least -30, - 20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90 °C. In some embodiments, the ammonia electrolysis system is designed to function at temperatures of at most 10, 20, 30, 40, 50, 60, 70, 80 °C.

[0139] In some embodiments, the ammonia liquefier described herein may additionally serve as an electrolyte, enhancing the ionic conductivity of ammonia during electrolysis.

[0140] In some embodiments, and with reference to FIG.7, the ionic conductivity of the liquefied ammonia compositions described herein is in the range of about 20 to about 250 mS / cm. In some embodiments, the ionic conductivity of the liquefied ammonia compositions is 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, or 250 mS / cm. In some embodiments, the ionic conductivity of the liquefied ammonia compositions is about 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, or 250 mS / cm. In some embodiments, the ionic conductivity of the liquefied ammonia compositions is at least 20, 25, 30, 40, 50, 60, 80, 100, 150, 200, or 250 mS / cm. In some embodiments, the ionic conductivity of the liquefied ammonia compositions is no more than 250, 230, 200, 180, 150, 120, 100, 80, 60, or 40 mS / cm. In some embodiments, the range of the ionic conductivity of the liquefied ammonia compositions may vary depending on the temperature, ammonia concentration, or specific AnQmcomposition used in the formulation. In further embodiments, the ionic conductivity may be measured without the use of a supporting electrolyte, demonstrating the intrinsic ion-conductive nature of the liquefied ammonia composition.

[0141] In some embodiments, one or more supporting electrolytes or chemical additives may be incorporated into the ammonia preparation unit or the resulting liquefied ammonia composition to enhance ionic conductivity, thermal stability, or compatibility with electrochemical operation. Suitable additives are described in further detail in the additives section herein.

[0142] In some embodiments, and with reference to FIG.8, the dynamic viscosity of the liquefied ammonia compositions is in the range of about 8 to about 25 centipoise (cP). In someWSGR Docket No.70778-702.601 embodiments, the dynamic viscosity of the liquefied ammonia compositions is 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 cP. In some embodiments, the dynamic viscosity of the liquefied ammonia compositions is about 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 cP. In some embodiments, the dynamic viscosity of the liquefied ammonia compositions is at least 8, 9, 10, 12, 15, 18, 20, or 22 cP. In some embodiments, the dynamic viscosity of the liquefied ammonia compositions is no more than 25, 24, 22, 20, 18, 16, 14, 12, 10, or 8 cP. In some embodiments, the viscosity of the liquefied ammonia composition remains stable across a temperature range of about –10^°C to about 60^°C, and supports effective mass transport and pumping within electrochemical systems. In further embodiments, the flowable viscosity enables continuous circulation of the composition through electrochemical compartments, gas-liquid separators, and ammonia preparation units without clogging or phase separation. The flowability of the composition further supports efficient contact with catalyst surfaces and enhances ammonia diffusion during electrolysis.

[0143] In some embodiments, the liquefiers described herein retain their structural and functional properties over repeated cycles of ammonia electrolysis and re-preparation process. Following ammonia conversion into hydrogen and nitrogen gases within the electrochemical cell, the remaining liquid may be returned to an ammonia preparation unit where the remaining liquid may be re-saturated with ammonia to restore its functionality. In some embodiments, the remaining liquid comprises liquefied ammonia composition. The regenerated composition may be then recycled to the electrochemical cell for continued operation. In some embodiments, the system maintains stable performance over at least 5, 10, 15, 20, 25, 30, 40, or 50 cycles. In further embodiments, the system operates over at least 75, 100, 150, 200, 250, 300, 400, or 500 cycles with no measurable precipitation or loss in liquefaction functionality. In certain embodiments, ammonia re-saturation restores the composition’s capacity without the need to add fresh liquefier (e.g., in order to include more of the included AnQmcompound). In some embodiments, minor performance loss—e.g., less than 5%, 3%, or 1%—may occur after prolonged use, and may be counteracted by replenishing a small portion of the liquefier or adjusting the ammonia saturation conditions. This regenerative cycling process enables continuous or extended batch operation while preserving the chemical activity, ionic conductivity, and flowability of the liquefied ammonia medium.

[0144] In certain configurations, liquefied ammonia may be present at both the anode and cathode compartments. In other configurations, liquefied ammonia may be present at only one electrode, either the anode or the cathode—while the other electrode is in contact with a different ammonia-containing medium, such as aqueous ammonia or ammonia dissolved in an organicWSGR Docket No.70778-702.601 solvent. These hybrid or asymmetric arrangements may be employed depending on system design, process integration, or application-specific requirements.

[0145] In some embodiments, one of the ammonia preparation units described herein may be replaced by an electrolyte preparation unit configured to deliver a non-ammonia-based electrolyte solution to the electrochemical cell. In certain configurations, the electrolyte preparation unit may be operatively connected to the cathodic compartment and supply an aqueous acidic solution—such as sulfuric acid, hydrochloric acid—to enable proton-driven hydrogen evolution reactions (HER) at the cathode. In other configurations, the electrolyte preparation unit delivers an alkaline aqueous solution—such as potassium hydroxide (KOH), sodium hydroxide (NaOH), or ammonia-based bases—to the cathodic compartment to facilitate HER.

[0146] In some embodiments, the anodic compartment receives a liquefied ammonia composition while the cathodic compartment may be supplied with an acidic or alkaline electrolyte. These asymmetric or hybrid configurations may be selected based on catalyst compatibility, efficiency optimization, or desired cell voltage. The electrolyte preparation unit may optionally include temperature regulation, pH control, or additive dosing to support stable operation over time. The use of an electrolyte preparation unit in place of an ammonia preparation unit provides system design flexibility while still enabling efficient hydrogen production. ELECTROLYTIC CELL

[0147] In some embodiments, the system comprises an electrochemical cell (e.g., electrochemical cell 108 of FIG.1, electrochemical cell 208 of FIG.2, electrochemical cell 308 of FIG.3, and electrochemical cell 408 of FIG.4) configured for the electrochemical conversion of ammonia into hydrogen and nitrogen gases. The electrochemical cell includes an anodic compartment and a cathodic compartment, each of which may be configured to receive one or more liquefied ammonia compositions and / or optional supporting electrolytes suitable for oxidation and / or reduction reactions.

[0148] In some embodiments, the anodic and cathodic compartments may be separated by a membrane or porous separator (e.g., separator 209 of FIG.2, separator 309 of FIG.3, and separator 409 of FIG.4) that facilitates selective ionic transport and maintains physical separation of the evolved hydrogen and nitrogen gases. In other embodiments, the electrochemical cell may operate without a separator (e.g., separator 209 of FIG.2, separator 309 of FIG.3, and separator 409 of FIG.4), and gas products from the anodic and cathodicWSGR Docket No.70778-702.601 compartments may be physically or operationally separated through cell design, directional flow, or downstream purification systems.

[0149] In some embodiments, the electrochemical cell includes a power supply operatively connected to electrodes disposed within the anodic and cathodic compartments. The power supply may be configured to deliver a constant or variable voltage sufficient to drive ammonia oxidation at the anode and hydrogen evolution at the cathode. In some embodiments, the power supply comprises a DC source, a battery, a potentiostat, or a programmable power supply. The electrodes may comprise one or more conductive materials including at least one metal selected from nickel, cobalt, iron, copper, chromium, platinum, iridium, ruthenium, rhodium, and manganese, or alloys or combinations thereof, as described in this disclosure. The electrodes may be planar, porous, supported, or self-standing.

[0150] In some embodiments, the electrochemical system includes a dryer configured to remove moisture from ammonia gas prior to introduction of ammonia gas into the ammonia preparation unit. In certain implementations, a drying step may alternatively or additionally be applied to the liquefied ammonia downstream of the preparation unit, prior to introduction of liquefied ammonia into the electrolytic cell.

[0151] In some embodiments, the electrochemical cell may be configured for continuous-flow or batch operation. The cell may be constructed as a single integrated unit or as a modular assembly comprising fluidically or structurally connected anodic and cathodic compartments. Multiple electrochemical cells may be arranged in series or parallel configurations to enhance throughput or enable system scaling.

[0152] In some embodiments, the electrochemical cell further includes sealing gaskets, electrical terminals, flow ports, thermal regulation components, and pressure or flow control elements. The design of the anodic compartment, cathodic compartment, membrane or separator, and power delivery system may be configured independently based on factors including material compatibility, electrochemical performance, reaction kinetics, or operational constraints.

[0153] In some embodiments, the ammonia electrolytic unit is designed to function at pressures up to about 15 atm. In some embodiments, the ammonia electrolytic unit is designed to function at pressures in the range of about 0.001 to about 10 atm. In some embodiments, the ammonia electrolytic unit is designed to function at pressures in the range of about 0.01 to about 5 atm. In some embodiments, the ammonia electrolytic unit is designed to function at pressures of 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, the ammonia electrolytic unit is designed to function at pressures of about 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,WSGR Docket No.70778-702.601 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, the ammonia electrolytic unit is designed to function at pressures of at least 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, the ammonia electrolytic unit is designed to function at pressures of no more than 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 atm. In some embodiments, the ammonia electrolytic unit is designed to function at temperatures ranging from about -30 °C to about 140 °C. In some embodiments, the ammonia electrolytic unit is designed to function at temperatures of -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, or 140 °C. In some embodiments, the ammonia electrolytic unit is designed to function at temperatures of about -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, or 140 °C. In some embodiments, the ammonia electrolytic unit is designed to function at temperatures of at least -30, -20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, or 140 °C. In some embodiments, the ammonia electrolytic unit is designed to function at temperatures of at most 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, or 140 °C.

[0154] In some embodiments, the ammonia electrolytic unit is designed to operate continuously for at least 10, 50, 100, 500, or more hours. In some embodiments, the ammonia electrolytic unit is designed to operate continuously for about 10, 50, 100, 500, or more hours. ANODIC COMPARTMENT

[0155] In certain aspects, the present disclosure provides a system and method for hydrogen production via electrochemical conversion of ammonia. The system may comprise at least one electrochemical cell having an anodic compartment that includes an anode, one or more liquefied ammonia composition, and optionally one or more supporting electrolytes. The anode is configured to facilitate the oxidation of ammonia through the ammonia oxidation reaction (AOR), generating electrons and reaction products as described herein.

[0156] In some embodiments, the anodic half-reaction occurring within the anodic compartment may be represented by Reaction Formula I, in which ammonia (NH₃) is oxidized to produce nitrogen gas (N₂), ammonium ions ([NH₄]⁺), and electrons (e⁻): 8 NH3 → N2 + 6 [NH4]++ 6 e–(Reaction Formula I)

[0157] In some embodiments, the stoichiometry of the reaction may vary based on the electrolyte composition, pH, operating temperature, or applied potential.

[0158] In some embodiments, a conductive component at the anode may comprise one or more materials that are catalytically active toward the ammonia oxidation reaction (AOR). The anodeWSGR Docket No.70778-702.601 may include at least one catalyst (e.g., a metal, alloy, or catalytic composite) capable of facilitating electron transfer and sustaining AOR under the operational conditions of the electrochemical cell.

[0159] In some embodiments, the AOR catalyst may comprise one or more elements or compounds. In some embodiments, the one or more elements or compounds may include a plurality of elements and / or compounds. In some embodiments, the one or more elements or compounds comprises a plurality of elements or a plurality of compounds. In some embodiments, the AOR catalyst comprises an alloy. While certain embodiments, of the AOR catalyst are described, these AOR catalysts are exemplary and other AOR catalysts may be used. In some embodiments, the AOR catalyst may comprise one or more metals selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), chromium (Cr), platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh), and manganese (Mn), or combinations or alloys thereof. The catalyst may be configured as a binary, ternary, or multi-metallic, or heterogeneous composite designed to enhance AOR activity, conductivity, and / or durability under the operating conditions of the ammonia electrolysis system. In certain embodiments, the catalyst metals may be present in elemental form, as alloys, or in chemically bound forms including oxides, nitrides, phosphides, carbides, selenides, borides, hydroxides, or combinations thereof. In certain embodiments, the catalyst may include mixtures of metallic and non-metallic forms.

[0160] In some embodiments, the AOR catalyst may comprise a composition including platinum (Pt), and one or more additional metal selected from the group consisting of iridium (Ir), cobalt (Co), iron (Fe), copper (Cu), ruthenium (Ru), rhodium (Rh), manganese (Mn), and nickel (Ni). The one or more additional metal may be present at a molar ratio relative to Pt in the range of about 0.1:1 to about 10:1, such as 0.1:1, 0.5:1, 1:1, 2:1, 5:1, or 10:1. In some embodiments, the catalyst may consist essentially of Pt, Ir, and the one or more additional metals described herein. The one or more additional metals may function as a co-catalyst, dopant, alloy agents, structural promoter, or electronic modifier to improve AOR activity, corrosion resistance, or electron transport properties.

[0161] In some embodiments, the AOR catalyst may comprise a binary alloy of platinum (Pt) and iridium (Ir). The molar ratio of Pt to Ir may range from about 1:1 to about 10:1, including ratios such as 1:1, 2:1, 3:1, 5:1, or 10:1. In some embodiments, the molar ratio of Pt to Ir may be about 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. In some embodiments, the molar ratio of Pt to Ir may be approximately 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. In some embodiments, the molar ratio of Pt to Ir may be at least 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1. In some embodiments, the molar ratio of Pt to Ir may be no more than 10:1, 9:1, 8:1, 7:1,WSGR Docket No.70778-702.601 6:1, 5:1, 4:1, 3:1, 2:1, or 1:1. The catalyst may include a stoichiometric or near-stoichiometric Pt–Ir formulation optimized for catalytic efficiency and long-term stability in liquefied ammonia media.

[0162] In some embodiments, the AOR catalyst may specifically comprise platinum (Pt), iridium (Ir), and nickel (Ni), optionally as a binary (Pt–Ni, Ir–Ni) or multi-metallic composition (Pt–Ir– Ni). The Ni content may be present at a molar ratio of about 0.1:1 to about 10:1 relative to Pt or to the combined Pt and Ir content. The catalyst may consist essentially of Pt and Ni, Ir and Ni, or Pt, Ir, and Ni, wherein nickel may function as an alloying component, a catalytic promoter, or a structural stabilizer. In some embodiments, the Pt–Ir–Ni catalyst system may be formulated as a multi-metallic alloy, an intermetallic compound, or a supported composite. The catalyst may be synthesized by co-deposition, alloying, impregnation, thermal decomposition, or other methods known in the art. In certain embodiments, the molar ratio of Pt to Ir may range from about 1:1 to about 10:1, while the Ni content may vary as described above to modulate the catalyst’s electrochemical activity, overpotential, or longevity under ammonia oxidation conditions.

[0163] In some embodiments, the AOR catalyst may comprise or consist essentially of an iron- based alloy including one or more selected from chromium (Cr), nickel (Ni), carbon (C), manganese (Mn), and optionally molybdenum (Mo). The alloy may serve as an active electrocatalyst, a catalytic substrate, or a structural support exhibiting intrinsic or surface- modified catalytic activity for ammonia oxidation under electrochemical conditions. The alloy may be austenitic, ferritic, martensitic, duplex, or precipitation-hardened, and may be prepared by conventional metallurgical techniques including casting, sintering, powder metallurgy, or additive manufacturing.

[0164] In some embodiments, the catalyst may comprise or consist essentially of an alloy having the general formula Fe-X / Ni-Y / Cr-Z / C-W where X, Y, Z, and W represent weight percentages and independently range from about 0.1 wt.% to about 100 wt.%. In certain embodiments, the alloy may further comprise one or more additional elements such as manganese (Mn) and molybdenum (Mo), present in amounts ranging from about 0.1 wt.% to about 13.0 wt.% for Mn and about 0.1 wt.% to about 3.0 wt.% for Mo. The total composition may be adjusted to maintain electrochemical stability and catalytic functionality under the ammonia oxidation conditions described herein. The invention is not limited to the specific percentages disclosed herein, and minor variations in composition may be present depending on the alloy grade or manufacturing source.

[0165] In some embodiments, Fe may serve as the balance element, comprising approximately 60 wt.% to 90 wt.%, such as about 60, 65, 70, 75, 80, 85, or 90 wt.%, of the alloy composition. InWSGR Docket No.70778-702.601 some embodiments, the chromium content may range from about 8 wt.% to about 25 wt.%, such as about 8, 10, 12, 14, 16, 18, 20, 22, or 25 wt.%. In some embodiments, the nickel content may range from about 0.1 wt.% (e.g., 0.1, 0.2, 0.3, 0.5, or 1.0 wt.%) up to about 20 wt.% (e.g., 2, 4, 6, 8, 10, 12, 14, 16, 18, or 20 wt.%). In some embodiments, the carbon content may range from about 0.05 wt.% to about 2.1 wt.%, including values such as 0.05, 0.1, 0.2, 0.3, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, or 2.1 wt.%. In some embodiments, the manganese content may range from about 0.1 wt.% to about 13.0 wt.%, such as about 0.1, 0.3, 0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 7, 9, 11, or 13 wt.%. In some embodiments, the manganese content may be no more than 4.0, 3.0, 2.0, or 1.0 wt.%. In other embodiments, the alloy may be substantially manganese-free. In some embodiments, the molybdenum (Mo) content may range from about 0.1 wt.% to about 3.0 wt.%, such as about 0.1, 0.5, 1.0, 1.5, 2.0, 2.5, or 3.0 wt.%. Molybdenum may enhance pitting resistance and electrochemical durability. In other embodiments, the alloy may be substantially molybdenum-free. In other embodiments, the alloy may be substantially free of both Mn and Mo.

[0166] In certain embodiments, an exemplary composition of the AOR-active alloy comprises chromium in the range of about 15 wt.% to about 20 wt.%, carbon in the range of about 0.5 wt.% to about 1.3 wt.%, and nickel in the range of about 0.1 wt.% to about 6 wt.%, with iron as the predominant balance, comprising approximately 70 wt.% to 85 wt.% of the total composition. In some embodiments, the alloy may further include optional manganese and / or molybdenum in total amounts of up to about 1 wt.% and 3.0 wt.%. Such compositions have been observed to exhibit enhanced activity toward the ammonia oxidation reaction (AOR) under the electrolysis conditions disclosed herein.

[0167] In some embodiments, chromium is included to promote enhanced passivation, corrosion resistance, and catalytic durability during operation in ammonia-rich, alkaline, or neutral media. Manganese may improve microstructure stability and electronic conductivity, while molybdenum may enhance pitting resistance and maintain performance in aggressive electrolyte environments. In some embodiments, the carbon content may contribute to grain boundary stability, hardness, and catalytic surface reconstruction. The inclusion of nickel may tune the electronic structure of the active sites and reduce oxidation-induced degradation, especially when present even at low concentrations.

[0168] In some embodiments, the catalyst surface may be modified to enhance catalytic activity toward ammonia oxidation. Surface treatments may include one or more of mechanical polishing, sandblasting, plasma treatment, laser etching, electrochemical activation, or chemical etching. In some embodiments, surface roughening or activation may be performed using acid-based etching solutions comprising hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), orWSGR Docket No.70778-702.601 mixtures thereof. In some embodiments, acid etching may be conducted at temperatures ranging from about 10^°C to about 80^°C for durations of 5 to 60 minutes, depending on the alloy composition and surface condition.

[0169] In certain embodiments, acid or electrochemical treatments may remove passive oxide layers, increase surface roughness, expose catalytically active grain boundaries, or modify surface chemistry to enhance electrochemical performance. In some embodiments, plasma- assisted nitridation or carburization may be used to form catalytically active surface layers enriched in nitrogen or carbon, improving conductivity and ammonia oxidation activity.

[0170] In some embodiments, the catalytically active elements in the as described alloy or other may be present in various chemical forms, including elemental metals, metal oxides, metal nitrides, metal phosphides, metal carbides, metal borides, or combinations thereof. In some embodiments, surface-bound nickel, iron, or cobalt species may exist in oxidized states (e.g., NiO, Fe₂O₃, Co₃O₄), nitridated forms (e.g., Ni₃N, Fe₄N), or phosphidic forms (e.g., Ni₂P, FeP), depending on pretreatment conditions or electrolyte composition. In some embodiments, these surface species may form in situ during activation or during electrochemical cycling. In other embodiments, the modified forms may be pre-deposited or intentionally synthesized through thermal, plasma, or chemical processing steps.

[0171] In some embodiments, the iron-based alloy catalyst (e.g., Fe-X / Ni-Y / Cr-Z / C-W, with optional Mn and / or Mo) may serve as the sole catalytic material for ammonia oxidation. In other embodiments, the alloy may be used in conjunction with one or more catalytic elements selected from platinum (Pt), iridium (Ir), cobalt (Co), ruthenium (Ru), rhodium (Rh), or other metals disclosed herein. The combination may be in the form of a coating, an alloy, a dopant, a nanostructured layer, or a heterogeneous surface complex. In some embodiments, such catalytic enhancements may be introduced by chemical deposition, electroplating, thermal spraying, physical vapor deposition (PVD), chemical vapor deposition (CVD), or atomic layer deposition (ALD).

[0172] In some embodiments, the added catalytic material may be present in an amount of about 0.01 wt.% to about 30 wt.%, such as about 0.01, 0.1, 0.5, 1, 2, 5, 10, 15, 20, 25 or 30 wt.%. In some embodiments, the catalyst system may be structured as a bimetallic or trimetallic composite where one or more noble metals are dispersed across the surface of the iron-based alloy to form a synergistic active site architecture.

[0173] In some embodiments, the iron-based alloy may be partially nitrided, oxidized, or phosphidized, such that some metal elements exist in the form of metal oxides, nitrides, phosphides, or combinations thereof. These surface modifications may further enhance catalyticWSGR Docket No.70778-702.601 performance by altering electronic structure, introducing defect sites, or modifying ammonia adsorption energetics.

[0174] In some embodiments, the anodic oxidation catalyst may comprise one or more binary metal oxides selected from manganese oxide (MnO), nickel oxide (NiO), tin oxide (SnO), cobalt oxide (CoO), iridium oxide (IrO), iron oxide (FeO), indium oxide (In₂O₃), and ruthenium oxide (RuO₂). In some embodiments, ternary oxides or mixed-metal systems may be employed, including but not limited to nickel-iron oxide (NiFeO^), nickel-lanthanum oxide (NiLaO^), and lanthanum-cobalt oxide (LaCoO₃).

[0175] In some embodiments, phosphate-based catalysts such as iron phosphate (FePO₄), manganese phosphate (MnPO₄), or cobalt phosphate (CoPO₄) may be utilized. In other embodiments, selenide-based catalysts including nickel selenide (NiSe^) and cobalt selenide (CoSe^) may be employed. The catalyst may also comprise metal hydroxides, nitrides, or molecular metal complexes such as ruthenium complexes or iron coordination compounds. In certain embodiments, two or more catalytic materials may be combined as physical mixtures, layered structures, or heterojunctions to improve ammonia oxidation efficiency, activation energy, and catalyst lifetime. The choice of material may depend on compatibility with the electrolyte system and stability under operating conditions of liquefied ammonia electrolysis.

[0176] In some embodiments, the anode may comprise a composite structure formed by integrating one or more ammonia oxidation catalysts with a conductive substrate. The conductive substrate may be selected to provide mechanical integrity, electrical conductivity, and chemical compatibility with the ammonia electrolysis environment. Suitable substrates may be metallic, carbon-based, ceramic, or combinations thereof. Examples of conductive substrates include, but are not limited to, carbon paper, graphite plates, nickel foam, nickel–molybdenum foam, iron– nickel foam, stainless steel mesh, and conductive oxides. The catalyst may be applied onto or embedded into the substrate using fabrication techniques such as spraying, sintering, electroplating, slurry coating, dip coating, or thermal deposition.

[0177] In certain embodiments, the conductive substrate may comprise carbon-based materials, including graphene, carbon nanotubes (CNTs), activated carbon, carbon black, carbon felt, carbon cloth, glassy carbon, or boron-doped diamond. In other embodiments, the substrate may comprise metal-based or conductive metal oxide materials. Examples of conductive metal oxides include indium tin oxide (ITO), fluorine-doped tin oxide (FTO), and aluminum-doped zinc oxide (AZO). The conductive substrate may be planar, porous, or three-dimensionally structured (e.g., foam, mesh, felt, woven, or textile) to enhance catalyst dispersion and electrochemical surface area.WSGR Docket No.70778-702.601

[0178] In some embodiments, the conductive substrate may exhibit a pore size ranging from about 1 micron to about 500 microns. In some embodiments, the pore size may be about 1, 5, 10, 25, 50, 75, 100, 150, 200, 250, 300, 350, 400, 450, or 500 microns. In some embodiments, the pore size may be at least 1, 5, 10, or 50 microns. The thickness of the substrate may range from about 50 microns to about 5,000 microns (i.e., 0.05 mm to 5 mm). In some embodiments, the thickness may be about 50, 100, 200, 300, 400, 500, 750, 1,000, 1,500, 2,000, 3,000, 4,000, or 5,000 microns. In further embodiments, the substrate thickness may be at least 100, 500, or 1,000 microns. In one example, titanium foam, stainless-steel mesh may be employed as the underlying support for the electrocatalyst layer. In another example, carbon cloth may be employed as the underlying support for the electrocatalyst layer. in some embodiments, substrates may be chemically or thermally treated prior to catalyst application to improve wettability, adhesion, or electronic connectivity.

[0179] In some embodiments, the catalyst may be deposited onto the substrate using techniques such as spray coating, dip coating, drop casting, blade coating, doctor blading, inkjet printing, slurry casting, hydrothermal, or electrodeposition. In one embodiment, a spray-coating method may be used in which the catalyst ink—comprising metal catalyst, and / or binders, and solvent— is uniformly sprayed onto the substrate. After deposition, the catalyst layer may be dried, annealed, sintered, or chemically reduced. The resulting layer may have a thickness ranging from 1 µm to 200 µm.

[0180] In some embodiments, the catalyst composition may include one or more metals as described in this disclosure, supported by carbonaceous materials. In some embodiments, platinum supported on carbon (Pt–C) or co-supported platinum and iridium on carbon (Pt–Ir-–C) may be employed. The carbon support may be selected from Vulcan XC-72, carbon black, activated carbon, acetylene black, and graphene-based materials. The total catalyst composition may contain from about 5 wt.% to about 80 wt.% of the catalytic metal(s), with the remainder comprising the carbon support. In some embodiments, the metal loading may be about 5, 10, 20, 30, 40, 50, 60, 70, or 80 wt.%. In Pt–Ir–C catalysts, the molar ratio of Pt to Ir may range from about 1:1 to 10:1, including values such as 1:1, 2:1, 3:1, 5:1, or 10:1. In some embodiments, this catalyst layer is further deposited onto a conductive substrate as described above to form a complete anode assembly.

[0181] In some embodiments, the AOR catalyst composition may further comprise one or more polymeric binders to facilitate adhesion to the conductive substrate and ensure mechanical integrity. Suitable binders may include, but are not limited to, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), Nafion™, and similar polymeric materials. The binder contentWSGR Docket No.70778-702.601 may range from about 1 wt.% to about 30 wt.% of the total catalyst composition, such as about 1, 3, 5, 10, 15, 20, or 30 wt.%, depending on the desired porosity, flexibility, and electronic conductivity of the final electrode structure.

[0182] In some embodiments, the anode may operate in direct contact with the liquefied ammonia electrolyte described in this disclosure. In certain embodiments, the liquefied ammonia may serve as the sole electrolyte or may include one or more supporting electrolytes as previously described in the electrolyte section. The electrolyte composition and conditions may be selected to optimize anodic performance, conductivity, and stability under ammonia oxidation conditions. CATHODIC COMPARTMENT

[0183] In certain aspects, the present disclosure provides a method and system for hydrogen production from ammonia, wherein the electrolytic cell unit comprises at least one electrochemical cell including a cathodic compartment. The cathodic compartment may comprise liquefied ammonia, a cathode, and optionally a supporting electrolyte configured to facilitate proton transport and hydrogen gas evolution.

[0184] In some embodiments, the cathodic half-reaction corresponds to the hydrogen evolution reaction (HER), wherein hydrogen ions (H⁺) and / or ammonium ions ([NH₄]⁺) are electrochemically reduced to generate hydrogen gas. In certain embodiments, the HER may proceed via the following reaction pathway: 6[NH₄]⁺ + 6 e⁻ → 3 H₂ + 6 NH₃ (Reaction Formula II)

[0185] When combined with the anodic ammonia oxidation described in Reaction Formula I, the overall net reaction of the system may be summarized as: 2NH₃ → N₂ + 3 H₂ (Reaction Formula III)

[0186] The cathodic HER may vary based on the electrolyte composition (e.g., ammonium-rich, acidic or alkaline), pH, applied potential, and system temperature.

[0187] In some embodiments, a conducting component at the cathode may include one or more metals that exhibit catalytic activity (e.g., a catalyst) toward the hydrogen evolution reaction (HER). These metals may serve as the catalytic surface, substrate, or both.

[0188] In some embodiments, the HER catalyst comprises one or more elements or compounds. In some embodiments, the one or more elements or compounds may include a plurality of elements and / or compounds. In some embodiments, the one or more elements or compoundsWSGR Docket No.70778-702.601 comprises a plurality of elements or a plurality of compounds. In some embodiments, the HER catalyst comprises an alloy. While certain embodiments, of the HER catalyst are described, these HER catalysts are exemplary and other HER catalysts may be used. In some embodiments, the HER catalyst may include at least one metal selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), platinum (Pt), palladium (Pd), iridium (Ir), ruthenium (Ru), rhodium (Rh), manganese (Mn), molybdenum (Mo), and gold (Au), including alloys or combinations thereof. The catalyst may be monometallic, bimetallic, or trimetallic, with metals integrated as alloys, layered structures, or core–shell configurations.

[0189] In some embodiments, the cathode may comprise a conductive material selected from metal foam, metal thin film, metal mesh, sintered metal, metal felt, carbon cloth, carbon paper, carbon fiber, and carbon felt. The structure may be planar, porous, or structured to increase surface area. In certain embodiments, the cathode comprises Ni foam, Ni-Mo foam, carbon paper, or stainless-steel mesh. The present invention is not limited to these examples, and any conductive material suitable for electron transport and gas evolution may be used.

[0190] In some embodiments, the cathode may further comprise a catalyst selected to promote HER (e.g., the HER catalyst as noted above.) In one embodiment, the HER catalyst may comprise a nickel alloy containing one or more metals selected from iron (Fe), ruthenium (Ru), platinum (Pt), molybdenum (Mo), manganese (Mn), cobalt (Co), copper (Cu), and silver (Ag). The Ni content may range from about 30 wt.% to 99 wt.%, such as about 50, 60, 70, 80, 90, or 95 wt.%, depending on the alloy composition and HER performance. In certain embodiments, the HER catalyst may comprise at least about 70 wt.% nickel (Ni), with the balance including one or more metals selected from the group consisting of iron (Fe), ruthenium (Ru), platinum (Pt), molybdenum (Mo), manganese (Mn), cobalt (Co), copper (Cu), and silver (Ag). Such compositions have been observed to exhibit effective catalytic activity for the hydrogen evolution reaction (HER) under the operational conditions described herein.

[0191] In some embodiments, the cathode may comprise a platinum-based catalyst, such as Pt supported on carbon (Pt–C), applied to a conductive substrate. In some embodiments, the Pt catalyst may be applied at a loading ranging from about 0.1 mg / cm² to about 2.0 mg / cm². In some embodiments, the catalyst loading may be about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, or 2.0 mg / cm². In some embodiments, the catalyst loading may be at least 0.1, 0.2, 0.5, 1.0, or 1.5 mg / cm². In other embodiments, the catalyst loading may be no more than 2.0, 1.5, 1.0, 0.75, or 0.5 mg / cm². The optimal catalyst loading may depend on the catalyst structure, electrode architecture, and liquefied ammonia composition.

[0192] In some embodiments, the cathode catalyst may comprise platinum (Pt) and at least oneWSGR Docket No.70778-702.601 or more additional metals selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), ruthenium (Ru), palladium (Pd), copper (Cu), and silver (Ag). In certain embodiments, the Pt content may range from about 10 wt.% to about 90 wt.%, such as about 10, 20, 30, 40, 50, 60, 70, 80, or 90 wt.%, with the balance comprising one or more of the aforementioned secondary metals. In some embodiments, the secondary metals content may range from about 1 wt.% to about 50 wt.%, such as about 1, 5, 10, 15, 20, 25, 30, 40, or 50 wt.%. In certain embodiments, the catalyst may be supported on a conductive substrate, including but not limited to carbon black, graphene, metal foam, or sintered mesh. The Pt-to-secondary-metals ratio may be tailored to enhance HER performance, stability, and compatibility with the liquefied ammonia electrolyte system.

[0193] In some embodiments, the HER catalyst composition may further comprise one or more polymeric binders to facilitate adhesion to the conductive substrate and ensure mechanical integrity. Suitable binders may include, but are not limited to, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), Nafion™, or similar polymeric materials. The binder content may range from about 0.5 wt.% to about 10 wt.% of the total catalyst composition, such as about 1, 3, 5, 10, 15, 20, or 10 wt.%, depending on the desired porosity, flexibility, and electronic conductivity of the final electrode structure. In some embodiments, the one or more polymeric binders comprises Nafion™.

[0194] In some embodiments, the cathode reduction catalyst may comprise one or more molecular species selected from organometallic complexes and heterocyclic organic compounds. The organometallic complex may include a metal center such as molybdenum (Mo), ruthenium (Ru), or rhenium (Re), coordinated with one or more ligands selected from carbon-, nitrogen-, oxygen-, or sulfur-based groups, including but not limited to carboxylates, phosphines, amines, nitriles, thiolates, and sulfides. In some embodiments, the catalyst may also comprise organic molecules with heterocyclic backbones, such as imidazole, pyridine, or other nitrogen-containing ring systems. These catalytic compounds may be employed individually or in combination, optionally supported on conductive substrates, to facilitate efficient hydrogen evolution in the cathodic compartment under the ammonia electrolysis conditions disclosed herein.

[0195] In some embodiments, the liquefied ammonia may be used as a standalone electrolyte without additional supporting electrolytes. In other embodiments, one or more supporting electrolytes may be added to enhance ionic conductivity or adjust physicochemical properties, as further described in the electrolyte section of this disclosure.

[0196] In certain embodiments, the cathodic compartment may comprise an aqueous solution of one or more alkaline hydroxides, such as potassium hydroxide (KOH), sodium hydroxideWSGR Docket No.70778-702.601 (NaOH), or lithium hydroxide (LiOH). The hydroxide concentration may range from about 0.1 M to about 10 M, including values such as 0.1, 0.5, 1, 2, 3, 5, or 10 M. In this configuration, a membrane or separator is used to prevent water crossover (which could otherwise participate in undesired oxidation reactions), gas mixing, or electrolyte imbalance.

[0197] In some embodiments, the catholyte may comprise aqueous ammonia with one or more alkaline additives such as KOH, NaOH, or LiOH. The concentration of aqueous ammonia may range from about 1 wt.% to about 35 wt.%, and the alkaline additive may be present at concentrations from about 0.1 M to about 10 M. In some embodiments, one or more supporting electrolytes may be included in the basic solution to enhance ionic conductivity. In this configuration, a membrane or separator is used to prevent water crossover, gas mixing, or electrolyte imbalance.

[0198] In some embodiments, the cathodic compartment may contain an acidic aqueous electrolyte. Suitable acids may include, but are not limited to, hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), phosphoric acid (H₃PO₄), and trifluoromethanesulfonic acid (triflic acid, CF₃SO₃H). The acid concentration may range from about 0.01 M to about 10.0 M. In some embodiments, the acid concentration may be about 0.01, 0.1, 0.5, 1.0, 2.0, 5.0, 6.0, 7.0, 8.0, 9.0, or 10.0 M. In other embodiments, the acid concentration may be at least 0.01, 0.1, 0.5, 1.0, or 5.0 M, or no more than 10.0, 8.0, 6.0, 4.0, or 2.0 M. In some embodiments, one or more supporting electrolytes may be included in the acidic solution to enhance ionic conductivity, buffer pH, or modulate electrode interface behavior. Suitable supporting electrolytes may include inert salts such as sodium sulfate (Na₂SO₄), lithium triflate (LiCF₃SO₃), or potassium chloride (KCl), among others. In this configuration, a membrane or separator is employed between the acidic cathodic compartment and the anodic compartment to prevent water crossover, maintain gas separation, and avoid undesired mixing of aqueous and ammonia-rich phases. This barrier may comprise a proton exchange membrane (e.g., Nafion), an anion exchange membrane, or other ion-permeable materials compatible with system chemistry. SEPARATOR

[0199] In certain aspects, the present disclosure provides a method and process for hydrogen production using ammonia, wherein the electrolytic cell unit may comprise at least one electrochemical cell that includes an anodic compartment and a cathodic compartment that are physically separated by a separator or membrane (e.g., separator 209 of FIG.2, separator 309 of FIG.3, and separator 409 of FIG.4). The separator may be configured to facilitate ionic conduction between the compartments while preventing or minimizing the direct crossover orWSGR Docket No.70778-702.601 mixing of the anolyte and catholyte. In certain embodiments, the separator may additionally function to maintain gas-phase separation, allowing for independent evolution and collection of hydrogen at the cathode and nitrogen at the anode without cross-contamination or back-diffusion of reactive species.

[0200] In some embodiments, the separator may comprise a membrane, porous diaphragm, or a multilayer laminate structure, configured to permit ion transport while inhibiting bulk fluid crossover. In certain embodiments, the separator may be selected from ionic exchange membranes, microporous polymeric films, porous ceramics, and chemically resistant composites. In some embodiments, a cation exchange membrane may be employed to facilitate selective migration of positively charged ionic species, such as protons (H⁺) or ammonium ions (NH₄⁺), depending on the electrolyte composition, system pH, and operating conditions. The choice of separator may be tailored to the specific electrochemical environment and may impact system efficiency, gas separation, and long-term durability.

[0201] In some embodiments, the separator may comprise, or be selected from, materials including polyethylene, polypropylene, polysulfone, polyamide, polyethersulfone (PES), polyvinylidene fluoride (PVDF), polyester, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), perfluoroethylene-propylene (FEP), ethylene-tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene (ECTFE), and polybenzimidazole (PBI). These materials may be used individually or as composites and may be fabricated into porous, non-porous, or reinforced membrane structures depending on chemical resistance, mechanical strength, and operating temperature requirements.

[0202] In some embodiments, the separator may comprise sulfonated polymers or copolymers, including but not limited to sulfonated polystyrene, sulfonated polyether ether ketone (sPEEK), sulfonated polyarylether ketone (sPAEK), sulfonated polybenzimidazole (sPBI), sulfonated polysulfone, sulfonated polyetherimide, sulfonated polyetherketone, and sulfonated polyphosphazene. In certain embodiments, the separator may comprise fluorinated ionomers, such as poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), or Nafion®. These materials may be selected based on their proton conductivity, thermal and chemical stability, and compatibility with the operating electrolyte.

[0203] In some embodiments, the separator may comprise a hydrophilic porous membrane or diaphragm configured to facilitate ionic conductivity while minimizing crossover of gases or electrolyte components. Suitable examples may include ceramic membranes, glass fiber filters, and porous insulating bodies comprising or filled with agar, zeolite, metal oxides (e.g., Al₂O₃, SiO₂, TiO₂), or chemically stable polymer blends. These materials may be fabricated intoWSGR Docket No.70778-702.601 symmetric or asymmetric structures with controlled pore architecture to regulate transport properties and mechanical integrity under operational conditions.

[0204] In some embodiments, the separator may include one or more membranes. In some embodiments, the one or more membranes comprises a porous membrane. In some embodiments, the one or more membranes comprises Nafion™. In some embodiments, the one or more membranes comprise Zirfon® UPT, a polysulfone-based membrane reinforced with zirconia particles. In some embodiments, the one or more membranes comprises both Nafion™ and Zirfon® UPT. Zirfon® UPT may offer high chemical resistance, robust mechanical strength, and sustained ionic conductivity, and may reduce the risk of gas bubble entrapment and membrane degradation during ammonia electrolysis. While certain membranes are described as being comprised by the separator, these membranes are exemplary, and other membranes may be suitable for use in the separator.

[0205] In some embodiments, the separator may be configured as a flat sheet, self-supporting film, tubular membrane, spiral-wound layer, or multilayer laminate, and may optionally be reinforced or supported on a structural frame or porous substrate to enhance dimensional stability and mechanical strength. The separator’s thickness may range from about 10^μm to about 1^mm, such as about 10, 25, 50, 75, 100, 250, 500, or 1000^μm. In some embodiments, the porosity may range from about 5% to about 80%, and the ionic area resistance may be less than about 5^Ω·cm², such as less than 5, 3, 1.5, 1.0, 0.5, or 0.1^Ω·cm², depending on the system requirements. In certain embodiments, the separator may possess controlled hydrophilicity or hydrophobicity, tailored to regulate electrolyte transport, prevent gas crossover, and maintain optimal ionic conductivity during operation.

[0206] In some embodiments, the separator may comprise a bipolar membrane (BPM). The BPM may include a cation exchange layer (CEL) and an anion exchange layer (AEL) arranged in direct contact, forming a junction that facilitates selective ionic transport across the membrane. In certain configurations, the cation exchange layer may face the cathodic compartment, while the anion exchange layer may face the anodic compartment. This configuration may enable selective ion transfer while minimizing crossover of undesired species such as ammonia, ammonium, or nitrogen intermediates.

[0207] The bipolar membrane may be employed in a range of system configurations, including dual-liquefied ammonia systems, where both the anodic and cathodic compartments contain liquefied ammonia, as well as hybrid electrochemical systems, where the cathodic compartment comprises acidic or alkaline aqueous electrolytes as disclosed herein. In such configurations, the BPM may serve to preserve pH differentials or ionic gradients between compartments whileWSGR Docket No.70778-702.601 supporting stable electrochemical performance.

[0208] In some embodiments, the separator may comprise a laminate or modular stack that includes: (i) a barrier layer configured to inhibit permeation of ammonia or ammonia containing species, and (ii) an ion-conductive layer configured to support selective ionic transport without enabling bulk solvent transfer. In some embodiments, the separator may comprise a laminate or modular stack that includes: (i) a barrier layer configured to inhibit permeation of ammonia or ammonia containing species, and (ii) an ion-conductive layer configured to support selective ionic transport without enabling bulk solvent transfer when the catholyte is an ammonia-free electrolyte such as an acidic and / or alkaline aqueous solution. The barrier layer may comprise one or more materials selected for their low permeability to ammonia, such as ceramics (e.g., alumina, zirconia) or fluoropolymer films (e.g., PTFE, ETFE, or PFA). The ion-conductive layer may comprise a proton-conducting polymer such as perfluorosulfonic acid (PFSA), polybenzimidazole (PBI), or sulfonated polyether ether ketone (sPEEK). In some embodiments, the laminate structure may be supported on a porous or inert substrate to improve mechanical stability under electrochemical operating conditions.

[0209] In some embodiments, the electrochemical cell may operate without a physical separator between the anodic and cathodic compartments. This configuration may be suitable when the electrolyte composition is identical or substantially similar in both compartments—for example, when using the same liquefied ammonia solutions in combination with one or more supporting electrolytes on both cathodic and anodic compartment. The absence of a separator may simplify system architecture, reduce component cost, and minimize manufacturing complexity. In such designs, the spatial separation of hydrogen and nitrogen product gases may be achieved downstream of the electrochemical cell using conventional gas separation and purification methods, including but not limited to pressure swing adsorption (PSA), membrane-based separation, cryogenic distillation, or hybrid separation systems. Because these systems are typically operated under anhydrous and oxygen-free conditions, the risk of forming flammable hydrogen–oxygen mixtures is mitigated, thereby enhancing operational safety compared to conventional water-based electrolysis systems. In such embodiments, the inter-electrode spacing may be minimized to reduce ohmic losses and maintain high current densities. In some embodiments, the distance between the anode and cathode may be less than about 5 mm, such as about 4 mm, 3 mm, 2 mm, 1 mm, or less, depending on the conductivity of the electrolyte and the mechanical design of the electrochemical stack. ADDITIVES AND SUPPORTING ELECTROLYTE

[0210] In certain aspects, this disclosure provides one or more additives that may be utilized toWSGR Docket No.70778-702.601 improve the ammonia liquefaction process. For example, the one or more additives may be added to the ammonia or the liquefied ammonia composition to increase the adsorption or liquefaction of ammonia, thus increasing the amount of ammonia able to be stored in liquefied form. These one or more additives may help stabilize vapor pressure and control the boiling point of the system. In some embodiments, the composition comprises one or more additives. In some embodiments, the composition comprises one additive.

[0211] In some embodiments, the additive comprises any compounds that could enhance the ammonia liquefaction process by stabilizing the liquefied ammonia, increasing the % of ammonia, or adjusting the desire properties including but not limited to boiling point, vapor pressure, viscosity, solubility, thermal stability, and electrical / electrolytic conductivity. The additives may stabilize the liquefied ammonia, thereby providing the ammonia that remains in the liquid state over a broader range of temperatures and pressures. ADDITIVES FOR OVERALL LIQUEFACTION EFFICIENCY

[0212] In some embodiments, the additives (primary additives) are selected from the group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), propanol (C₃H₇OH), butanol (C4H10O), dimethyl sulfoxide (C₂H₆OS), glycerol (C₃H₈O₃), acetic acid (CH₃COOH), dimethylformamide (C₃H₇NO), pyridine (C₅H₅N), ethylene glycol (C₂H₆O₂), methanol (CH₃OH), acetone (C₃H₆O), tetrahydrofuran (C₄H₈O), diethylamine (C₄H₁₁N), triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), acetonitrile (C2H3N), N-methyl-2-pyrrolidinone (C5H9NO), hexamethylphosphorous triamide (C6H19N3OP), nitromethane (CH3NO2), urea (CH4N2O), phenol (C6H6O), 2-pyrrolidone (C4H7NO), diisopropylamine (C6H15N), 1,4-dioxane (C4H8O2), and morpholine (C4H9NO).

[0213] In some embodiments, the additives are selected from the group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), glycerol (C₃H₈O₃) or triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), and ethylene glycol ((CH₂OH)₂). SUPPORTING ELECTROLYTE

[0214] In some embodiments, additives may be used to increase the ionic conductivity of liquefied ammonia. These additives may function as electrolytes (“supporting electrolytes”) and may not involve in any reaction on the cathodic and anodic compartment. In some embodiments, these supporting electrolytes are selected from a group consisting of metal halides (ML, where M is lithium, sodium, potassium, and L is I, Br, and Cl, or multiatomic moiety comprising at least one atom from group 15, 16, and 17 of periodic table). In some embodiments, these supporting electrolytes are selected from a group consisting of ammonium halides (NH4L, where L is I, Br,WSGR Docket No.70778-702.601 and Cl, or multiatomic moiety comprising at least one atom from group 15, 16, and 17 of periodic table such as CF3SO3-, PF6-).

[0215] In some embodiments, these supporting electrolytes are selected from a group consisting of sodium chloride (NaCl), sodium bromide (NaBr), potassium bromide (KBr), potassium chloride (KCl), potassium nitrate (KNO₃), lithium nitrate (LiNO₃), sodium nitrate (NaNO₃), ammonium nitrate (NH₄NO₃), ammonium Chloride (NH₄Cl), ammonium Bromide (NH₄Br), ammonium iodide (NH₄I), alkyl chloride (RCl), potassium hexafluorophosphate (KPF6), ammonium hexafluorophosphate (NH4PF6), sodium hexafluorophosphate (NaPF6), ammonium triflate (NH4CF3SO3), and sodium triflate (NaCF3SO3) . In some embodiments, the additive may also encompass substances such as lithium amide (LiNH2), ammonium amide (NH4NH2), potassium amide (KNH2), sodium sulfate (Na2SO4), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), or potassium hydroxide (KOH). In some embodiments, the additive may be selected from a group consisting of 1,3,5-trinitrobenzene (C₆H₃(NO₂)₃), 2,4,6-trinitroaniline (C₆H₂(NO₂)₃NH₂), tetranitromethane (C(NO₂)₄), sodium nitromethanide (CH₂NO₂Na), ammonium nitroethane (CH₃CH₂NO₂NH₄), nitroguanidine (CH₄N₄O₂), methyl nitramine (CH₃N₂O₂), sulfanilamide (C₆H₈N₂O₂S), cyanamide (CH₂N₂), phthalimide (C₆H₄(CO)₂NH), thiourea (CS(NH₂)₂), thiosemicarbazide (H₂NNHC(S)NH₂), benzamide (C₆H₅CONH₂), phenylacetamide (C₆H₅CH₂CONH₂), cyanocetamide (CH₂(CN)CONH₂), ethylamine hydrochloride (C₂H₅NH₂·HCl), and diethylamine ((C₂H₅)₂NH).

[0216] In some embodiments, to prepare ammonia in a liquid or gel phase such that ammonia suitable for electrolysis under ambient conditions, about 50 wt.% of one or more liquefiers including sulfamide (SO₂(NH₂)₂), about 40 wt.% propylene carbonate as a primary additive, and about 10 wt.% ammonium tetrafluoroborate (NH₄BF₄) as a supporting electrolyte may be used.

[0217] In some embodiments, the supporting electrolytes may be selected from a group consisting of various alkali metals in their cationic or metallic forms such as Li+or Li, ammonium cation, alkylammonium cation, halide ions, alkyl amines, nitrite, nitrate, phosphate, polyphosphate, perchlorate, silicate, sulfate, carbonate, borate, and tetraalkyl ammonium. In some embodiments, these supporting electrolytes may be selected from a group consisting of hydrazinium chloride (N2H5Cl) and hydrazinium bromide (N2H5Br), along with hydrazinium acetate and hydrazinium azide, and other derivatives of hydrazine.

[0218] In some embodiments, one or more supporting electrolytes may be used. In certain cases, the same additive may be employed at both the cathodic and anodic compartments. In other cases, supporting electrolytes may be used at the cathodic and anodic compartments, depending on their respective electrolytic activities.WSGR Docket No.70778-702.601

[0219] In some embodiments, the liquefied ammonia composition may contain up to about 50 % of additives by weight (e.g., 50 wt.%). In some embodiments, the liquefied ammonia may contain up to about 1 to about 25% of additives by weight, which comprise primary additives and / or supporting electrolytes. In some embodiments, the liquefied ammonia may contain up to about 1 to about 20% of additives by weight, which comprise primary additives and / or supporting electrolytes. In some embodiments, the liquefied ammonia may contain up to about 1 to about 15% of additives by weight, which comprise primary additives and / or supporting electrolytes.

[0220] In some embodiments, the liquefied ammonia may comprise the additives, which consist of primary and / or supporting electrolytes at a concentration of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 wt.%. In some embodiments, the liquefied ammonia may comprise the additives, which consist of primary and / or supporting electrolytes at a concentration of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 wt.%. In some embodiments, the liquefied ammonia may comprise the additives, which consist of primary and / or supporting electrolytes at a concentration of at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 wt.%. In some embodiments, the liquefied ammonia may comprise the additives, which consist of primary and / or supporting electrolytes at a concentration of no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 wt.%.

[0221] In some embodiments, the primary additives may modify the vapor pressure of ammonia by about 5% to about 40% when in contact with ammonia, depending on specific additive and its concentration. In some embodiments, the primary additives may modify the vapor pressure of ammonia by about 8% to about 20% when in contact with ammonia, depending on specific additive and its concentration. In some embodiments, the primary additives may modify the vapor pressure of ammonia by 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, or 40% when in contact with ammonia. In some embodiments, the primary additives may modify the vapor pressure of ammonia by about 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, or 40% when in contact with ammonia. In some embodiments, the primary additives may modify the vapor pressure of ammonia by at least 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, or 40% when in contact with ammonia. In some embodiments, the primary additives may modify the vapor pressure of ammonia by no more than 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, or 40% when in contact with ammonia.

[0222] In some embodiments, the supporting electrolytes may modify the ionic conductivity of liquefied ammonia by about 2 to about 100 times, depending on specific additive and itsWSGR Docket No.70778-702.601 concentration. In some embodiments, the supporting electrolytes may modify the ionic conductivity of liquefied ammonia by about 2 to about 50 times, depending on specific additive and its concentration. In some embodiments, the supporting electrolytes may modify the ionic conductivity of liquefied ammonia by 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50 times. In some embodiments, supporting electrolytes may modify the ionic conductivity of liquefied ammonia by about 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48 or 50 times. In some embodiments, supporting electrolytes may modify the ionic conductivity of liquefied ammonia by at least 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48 or 50 times. In some embodiments, the supporting electrolytes may modify the ionic conductivity of liquefied ammonia by no more than 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48 or 50 times.

[0223] In some embodiments, the additives may inherently possess ammonia liquefaction properties when employed in conjunction with an ammonia liquefier. In some embodiments, the additives may inherently enhance the liquefaction characteristics when employed in conjunction with an ammonia liquefier. In some embodiments, the additives may inherently enhance the ionic conductivity of liquefied ammonia when employed in conjunction with an ammonia liquefier. The combination of these additives, particularly those that alter the physical properties of ammonia, such as vapor pressure, boiling point, and ionic conductivity, is configured to optimize the ammonia electrolysis process for H2 and N2 production under a variety of operational conditions.

[0224] In some embodiments, the selection of supporting electrolytes is carefully tailored to correspond with the specific requirements of ammonia E-cracking and the nature of the catalysts used for hydrogen and nitrogen production. In certain embodiments where high ionic conductivity is required at the anodic compartment and platinum-based catalysts are employed, supporting electrolytes such as ammonium and / or sodium trifluoromethanesulfonate (NH4CF3SO3 and / or NaCF3SO3) may be preferred.

[0225] In some embodiments, the proportions of additives (either primary and / or supporting electrolytes) may be adjusted based on experimental data as part of the refinement process. This involves adjusting the ratios of ammonia liquefier compounds to specific additives to identify the optimal conditions that maximize ammonia liquefaction while preserving the structural integrity and reactivity of the resulting compound, as well as the efficiency of ammonia to H2and N2conversion through electrolysis.WSGR Docket No.70778-702.601 DOWNSTREAM GAS MANAGEMENT (ADSORBENT & GAS SEPARATION)

[0226] In certain aspects, the present disclosure provides a method and system for hydrogen production using ammonia, wherein the electrochemical cell is integrated with one or more downstream gas management units configured to isolate product gases and recover unreacted ammonia. These units may include gas–liquid separation modules (e.g., liquid / gas separation 312a and 312b of FIG.3 and liquid / gas separation 412a and 412b of FIG.4), ammonia-selective adsorbent units (e.g., adsorbent 422a and 422b of FIG.4), and gas purification components for hydrogen and nitrogen, tailored to the specific operating configuration (e.g., flow-through or non- flow).

[0227] In some embodiments, the cathodic compartment generates hydrogen gas (H₂), potentially accompanied by trace quantities of ammonia vapor (NH₃). In flow-through configurations, liquefied ammonia may serve both as electrolyte and gas carrier, producing an effluent stream containing liquefied ammonia, hydrogen gas, and ammonia vapor. The system may include a gas–liquid separator configured to disengage the gaseous phase from the bulk liquefied ammonia. Suitable gas–liquid separators may include gravity-based phase separation units, demister chambers, or structured disengagement vessels, operated under conditions that preserve the ammonia in its liquid state. The separated liquefied ammonia may be recirculated to the electrochemical system, while the evolved gases may be routed to further treatment.

[0228] In non-flow systems where no liquid exits the cathodic chamber, the gaseous output may primarily consist of hydrogen and residual ammonia vapor. This stream may be directed directly to ammonia adsorbent units without prior phase separation.

[0229] In some embodiments, the hydrogen–ammonia gas mixture may be passed through a first adsorbent unit configured to selectively remove residual ammonia from the hydrogen stream. The adsorbent material may comprise conventional ammonia-specific sorbents, including but not limited to metal halides, acidic porous solids, zeolites, activated carbon, ion-exchange resins, or other materials exhibiting selective affinity toward ammonia.

[0230] In some embodiments, the adsorbent unit may utilize liquefiers (e.g., comprising one or more (AnQm)) or ammonia liquefaction compositions (e.g., comprising AnQm·(NH₃)y ) as the adsorbent medium. In this configuration, the ammonia liquefiers compositions not only absorb ammonia that enters the adsorbent unit, thereby isolating hydrogen gas, but also induce in situ liquefaction, enabling immediate recovery and recirculation of residue ammonia vapor into the electrochemical system. This approach enhances overall system integration, simplifies process complexity, and improves ammonia utilization efficiency.

[0231] In certain embodiments, the AnQm-based adsorbent may comprise one or moreWSGR Docket No.70778-702.601 compositions that include at least one of lithium thiocyanate (LiSCN), ammonium thiocyanate (NH₄SCN), or sulfamide (NH₂SO₂NH₂). These compounds, either individually or as part of composite AnQm formulations, have demonstrated high ammonia recovery performance in bench- scale evaluations and are particularly well-suited for downstream hydrogen purification in ammonia-based electrolysis systems. The use of such materials as dual-function ammonia sorbents and liquefaction agents may enable simultaneous capture and liquefaction of ammonia vapor residue, offering potential advantages in simplifying system design and improving ammonia recovery efficiency in different gas purification applications (e.g., hydrogen purification in downstream gas processing of ammonia thermal cracking).

[0232] The resulting hydrogen gas, following ammonia removal, may be further purified using a downstream gas separation unit. Suitable purification technologies may include pressure swing adsorption, membrane-based filtration, cryogenic distillation, or combinations thereof. The purified hydrogen may then be directed to storage tanks, compression systems, or end-use devices (e.g., Fuel cell).

[0233] In some embodiments, the anodic compartment evolves nitrogen gas (N₂), which may also contain minor amounts of ammonia vapor residue. In flow-through configurations, where liquefied ammonia is used as the electrolyte and gas carrier, the effluent may include both liquid and gas phases. A gas–liquid separator may be positioned downstream of the anode outlet to isolate gaseous nitrogen and ammonia vapor from the bulk liquid phase. The recirculated liquefied ammonia may be returned to the system, while the gas stream proceeds to purification.

[0234] In some embodiments, the hydrogen product purity (dry, mole basis) is at least 80%. In some embodiments, the hydrogen product purity (dry, mole basis) is about 90% to about 99.99% hydrogen by volume. In some embodiments, the purity is at least about 90%, 95%, 99%, 99.5%, 99.9%, or 99.99% hydrogen by volume, The hydrogen may be fed directly to a loading / dispensing system and / or compressed, or, if desired, subjected to further purification to meet application-specific purity requirements.

[0235] In some embodiments, the nitrogen-containing gas stream may be passed through a second adsorbent unit configured to selectively capture residual ammonia. The adsorbent may again comprise AnQmcompositions, metal halides, acidic porous materials, zeolites, activated carbon, or other selective sorbents. The recovered ammonia may be re-liquefied and routed back into the electrochemical cycle, enhancing ammonia utilization efficiency and minimizing environmental release. The final nitrogen product may be stored or vented depending on the application.

[0236] In certain configurations where no separator is employed between the anodic and cathodicWSGR Docket No.70778-702.601 compartments (e.g., both compartments use identical liquefied ammonia compositions), the resulting gas stream may comprise a mixture of hydrogen, nitrogen, and ammonia vapor residue. In such cases, downstream gas–liquid separation and multi-stage adsorbent-based purification, as describe in this disclosure may be employed to recover ammonia and isolate the hydrogen and nitrogen components. Suitable separation technologies include PSA, cryogenic distillation, membrane separation, or combinations thereof.

[0237] In some embodiments, where the cathodic compartment comprises an aqueous alkaline or acidic electrolyte and does not contain ammonia or ammonia derivatives, the downstream gas stream may not require an ammonia-specific adsorbent unit. In such configurations, the cathodic effluent predominantly consists of hydrogen gas with minimal or no ammonia vapor, and subsequent purification may be performed using conventional gas purification techniques such as PSA or membrane separation, without the need for ammonia removal.

[0238] In some embodiments, the electrochemical system includes a power supply unit operatively connected to the anode and cathode, configured to apply an electrical potential sufficient to drive the electrochemical conversion of ammonia to hydrogen and nitrogen. The power supply may operate under constant voltage, constant current, or pulsed modes, depending on system requirements. In certain embodiments, the operational mode may be dynamically adjusted to optimize reaction kinetics, energy consumption, and system stability.

[0239] In some embodiments, the power supply unit may incorporate feedback control mechanisms configured to monitor and adjust the applied current and / or voltage based on real- time measurements of system parameters. Such parameters may include electrolyte composition, temperature, internal resistance, gas evolution rates, or electrode degradation. In some embodiments, the control system may utilize closed-loop algorithms to maintain target current densities or electrochemical potentials within specified operational ranges.

[0240] In some embodiments, the power supply may be configured to draw energy from conventional and / or renewable sources. Suitable energy sources may include grid electricity (via AC–DC conversion), solar photovoltaic modules, wind turbines, hydroelectric power, geothermal systems, or battery storage units. In some embodiments, a power management controller may be employed to integrate multiple energy inputs and ensure stable and continuous electrolysis operation, even under variable power supply conditions. It should be understood that the selection and combination of power sources are not intended to limit the scope of the invention, and any energy source capable of delivering the required electrical parameters may be employed.

[0241] In some embodiments, the system may include one or more electrical switches, relays, or circuit breakers configured to enable rapid activation and deactivation of the electrolysis process.WSGR Docket No.70778-702.601 These components may support safety interlocks, scheduled maintenance, or automated control logic for system start-up and shutdown procedures.

[0242] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. It is not intended that the invention be limited by the specific examples provided within the specification. While the invention has been described with reference to the aforementioned specification, the descriptions and illustrations of the embodiments herein are not meant to be construed in a limiting sense. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Furthermore, it shall be understood that all aspects of the invention are not limited to the specific depictions, configurations or relative proportions set forth herein which depend upon a variety of conditions and variables. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is therefore contemplated that the invention shall also cover any such alternatives, modifications, variations or equivalents. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby. EXAMPLES

[0243] The following examples are included for illustrative purposes only and are not intended to limit the scope of the invention. Example 1: Electrochemical System for Ammonia Electrolysis

[0244] In one example, an electrochemical system for ammonia electrolysis was assembled in accordance with the architecture described in the foregoing embodiments. The cell included an anodic compartment and a cathodic compartment separated by a porous separator. The anode catalyst was synthesized from a composition comprising platinum (Pt), and one or more additional metals selected from the group consisting of iridium (Ir), cobalt (Co), iron (Fe), copper (Cu), ruthenium (Ru), rhodium (Rh), manganese (Mn), and nickel (Ni). The catalyst precursor was mixed with carbon powder at a 40:60 catalyst-to-carbon weight ratio and subjected to hydrothermal treatment at 160^°C for 3 hours. The resulting product was collected and dried at 150^°C. To fabricate the anodic electrode, the dried catalyst powder was mixed with 6 wt.% polytetrafluoroethylene (PTFE) binder in a 9:1 ratio, then dispersed in a 1:1 (v / v) ethanol–water solution and sonicated for 30 minutes to yield a homogeneous catalyst ink. The ink was spray- coated onto as conductive substrate, as described in this disclosure, and dried at 140^°C for 2 hours.WSGR Docket No.70778-702.601

[0245] The cathodic electrode was fabricated using a similar process, wherein a commercially available 40 wt.% Pt / C catalyst was coated onto carbon cloth with PTFE binder via spray- coating. Liquefied ammonia was employed as the electrolyte in both compartments. The liquefied ammonia was prepared by absorbing anhydrous ammonia into liquefier materials comprising one or more compounds of the general formula AnQm, including but not limited to sulfamide. The resulting electrolyte was introduced into the electrochemical cell under ambient pressure and temperature conditions. The system was operated using a programmable DC power supply in a three-electrode configuration, wherein an Ag / AgCl reference electrode was placed adjacent to the anodic compartment to enable accurate analysis of electrochemical behavior. Current–voltage (I–V) characterization showed that an anodic potential of approximately 0.35 V versus Ag / AgCl, as shown in FIG.9A, was sufficient to initiate ammonia oxidation. Example 2: Flow-Through Electrolysis System with platinum based catalyst

[0246] In another example, the electrochemical system configuration was generally similar to that described in Example 1, with the following modifications based on the configurations disclosed herein. A flow-through architecture was employed, wherein the anodic and cathodic compartments were equipped with independent flow loops, each driven by a separate peristaltic pump. The electrolyte in each compartment consisted of liquefied ammonia prepared using liquefier materials comprising one or more compounds of the general formula AnQm, including but not limited to sulfamide, and further comprising approximately 20 wt.% of a supporting electrolyte to enhance conductivity.

[0247] The liquefied ammonia-based electrolyte was continuously circulated through the respective compartments during operation. Downstream of each compartment, gas–liquid separation units were installed to separate the evolved gaseous products from the circulating liquid electrolyte. The separated liquid phase, comprising the liquefied ammonia and supporting electrolyte, was returned to the corresponding compartment for recirculation. The gaseous effluents were directed to an ammonia adsorbent unit to capture any unreacted ammonia vapor. Ammonia adsorbent was carried out using an acidic solution comprising 0.5 M sulfuric acid (H₂SO₄), which acted as an effective absorbent to separate ammonia form product gas (N2 at the anodic part and H2at the cathodic part)

[0248] The electrochemical system was operated in a two-electrode galvanostatic configuration. A constant current density of approximately 25 mA / cm² was applied using a programmable DC power supply. Electrolysis was sustained for approximately 2 hours. The gaseous products were analyzed using an in-line gas analyzer, confirming the evolution of hydrogen at the cathode and nitrogen at the anode, consistent with the complete decomposition of ammonia. The faradaicWSGR Docket No.70778-702.601 efficiency for hydrogen generation was calculated to at least 80%. Example 3: Electrochemical System for Ammonia Electrolysis by Iron-based alloy electrode

[0249] In another example, an electrochemical system was assembled in a three-electrode configuration consistent with the general design described in Example 1. The working electrode comprised a mesh structure (400 mesh) fabricated from an iron-based alloy comprising approximately 15–20 wt.% chromium, 0.5–1.3 wt.% carbon, and 0.1–6 wt.% nickel, with iron as the predominant balance, constituting approximately 70–85 wt.% of the total alloy composition. The alloy also contained a total of approximately 2 wt.% manganese and molybdenum combined.

[0250] Prior to use, the alloy mesh was cleaned and activated by sonication in acetone for 30 minutes, followed by immersion in a 0.1 M hydrochloric acid (HCl) solution to remove surface oxides and contaminants. The electrode was then rinsed with deionized water and dried under ambient conditions before being used directly as the anodic catalyst in the electrochemical system.

[0251] A platinum-on-carbon (Pt / C) electrode was used as the cathode at the cathodic compartment separated from the anodic compartment using a membrane separator as described in this disclosure. An Ag / AgCl reference electrode was positioned adjacent to the working electrode at the anodic compartment to enable potential-resolved analysis. The electrolyte consisted of liquefied ammonia prepared using liquefier materials comprising one or more compounds of the general formula AnQm, including but not limited to sulfamide, as described in Example 1. One or more supporting electrolytes were included to enhance ionic conductivity, with the weight ratio of supporting electrolyte to AnQmcompound being approximately 20%.

[0252] Linear sweep voltammetry (LSV) was conducted to evaluate the electrochemical performance of the iron-based alloy. The onset of ammonia oxidation was observed at approximately 0.55 V vs. Ag / AgCl, as shown in FIG.9B. The electrode demonstrated stable activity during the test period with no evidence of passivation or visible corrosion. Example 4: Flow Electrolysis Using Nobel-metal-free (Iron-Based) Anode

[0253] In another example, the electrochemical system described in Example 2 was modified as follows. The system was operated in a two-electrode configuration using a galvanostatic current density of approximately 25 mA / cm², applied for a duration of approximately 2 hours under ambient temperature and pressure conditions.

[0254] The anodic electrode comprised a mesh structure (400 mesh) fabricated from an iron- based alloy having a composition as described in Example 3, including approximately 15–20WSGR Docket No.70778-702.601 wt.% chromium, 0.5–1.3 wt.% carbon, 0.1–6 wt.% nickel, and approximately 70–85 wt.% iron as the balance, along with approximately 2 wt.% total of manganese and molybdenum. The mesh electrode was cleaned and activated by sonication in acetone for 30 minutes followed by immersion in 0.1 M hydrochloric acid, rinsing, and air drying prior to use.

[0255] The cathodic electrode was prepared using a mixed-metal platinum catalyst. The cathode catalyst comprised platinum (Pt) and at least one additional metal selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), ruthenium (Ru), palladium (Pd), copper (Cu), and silver (Ag). The catalyst was synthesized via a polyol-based hydrothermal reaction, wherein approximately 2 mg / mL of carbon powder was suspended in a 50 mL mixture of ethylene glycol and deionized water. Metal precursors of Pt and one or more selected additional metals were added to the suspension, and the mixture was heated at 160^°C under reflux. The reaction progress was monitored by tracking the pH of the vapor-phase condensate. The reaction was terminated when the pH reached 7, typically after approximately 3 hours. The resulting product was collected, washed with isopropanol, and dried at 80^°C for 5 hours.

[0256] Prior to electrode fabrication, the dried catalyst powder was dispersed in a mixture of isopropanol and deionized water and subsequently was mixed with 6 wt.% PTFE binder at a 9:1 catalyst-to-binder ratio. The catalyst ink was sonicated for 30 minutes and air-sprayed onto carbon cloth, followed by drying at 140^°C for 2 hours to yield the cathodic electrode.

[0257] The anodic and cathodic compartments were separated by a membrane separator as described in this disclosure. Each compartment maintained an independent electrolyte circulation loop driven by peristaltic pumps. The electrolyte in both compartments consisted of liquefied ammonia prepared using liquefier materials comprising one or more AnQm-type compounds, including but not limited to sulfamide, combined with a supporting electrolyte at a weight ratio of at least 20% relative to the AnQm content. Gas–liquid separation units were positioned downstream of each compartment to separate the evolved gas from the circulating liquid phase. The separated electrolyte was recycled back to its respective compartment. The gaseous streams from the anodic and cathodic compartments were each passed through separate ammonia adsorbent units containing one or more solid-state AnQm-based adsorbents, including lithium thiocyanate (LiSCN), to capture residual ammonia vapor from both the nitrogen and hydrogen gas streams.

[0258] Gas analysis confirmed the evolution of hydrogen at the cathode and nitrogen at the anode. The faradaic efficiency for hydrogen production was calculated to at least 77%. No observable degradation or instability was detected in either electrode during the test period.WSGR Docket No.70778-702.601 Example 5: Ammonia Electrolysis Under Long-Duration Electrolysis Operation

[0259] In continuation of Example 4, the system was evaluated for extended-duration performance to assess durability of the components under prolonged operation. The electrochemical cell configuration, electrode materials, liquefied ammonia composition, electrolyte, and AnQm-based adsorbent units were all consistent with those described in Example 4. The system was operated continuously for 24 hours under ambient temperature and pressure in a two-electrode galvanostatic configuration at a current density of approximately 25 mA / cm². Electrolyte circulation, gas–liquid separation, and ammonia adsorption systems were maintained throughout the duration of the experiment. Hydrogen and nitrogen production remained stable over the 24-hour period, as verified by periodic in-line gas analysis. No significant loss of current efficiency or gas purity was observed. Post-operation inspection revealed no visible degradation in the membrane, electrode structure, or catalyst adhesion. The AnQm-based adsorbent beds showed partial saturation but maintained ammonia retention capacity over the full operating window. Example 6: Ammonia Electrolysis Under Long-Duration Electrolysis Operation

[0260] In another continuation of Example 4, the electrochemical system was evaluated for dynamic responsiveness and cycling durability under intermittent operational conditions. The cell configuration, electrode composition, liquefied ammonia composition, electrolyte formulations, membrane separator, and flow-loop design were identical to those described in Example 4. The system was subjected to repeated on–off cycling to simulate real-world conditions requiring rapid start-up and shutdown. A total of 100 cycles were conducted, each consisting of a 20-minute galvanostatic “on” period at a galvanostatic current density of approximately 25 mA / cm², followed by a 20-minute rest period with no applied current. Throughout the cycling test, the system maintained stable gas evolution and consistent performance, with a total Faradaic efficiency loss of less than 2% over the entire duration. Notably, after each rest period, the current response recovered rapidly, reaching approximately 90% of its prior steady-state value within 2 to 10 minutes of re-initiation. This fast electrochemical activation and recovery time contrasts sharply with conventional thermal ammonia cracking systems, which typically require at least 4 to 12 hours for warm-up. The results of this example highlight the superior dynamic response of the electrochemical ammonia cracking system and demonstrate the mechanical and catalytic resilience of the materials under cyclic load conditions. Example 7: Ammonia Electrolysis with Acidic Catholyte and Liquefied Ammonia Anolyte

[0261] In another example, the electrochemical system described in Example 4 was modified asWSGR Docket No.70778-702.601 follows. The anodic compartment and electrode were identical to those described in Example 3. The anode comprised a 400 mesh iron-based alloy containing approximately 15–20 wt.% chromium, 0.5–1.3 wt.% carbon, and 0.1–6 wt.% nickel, with iron as the predominant balance (70–85 wt.%), and approximately 2 wt.% total of manganese and molybdenum. The electrode was cleaned by sonication in acetone for 30 minutes followed by etching in 0.1 M hydrochloric acid, rinsed, and air-dried prior to use.

[0262] The cathodic electrode was prepared as described in Example 4, using a mixed-metal platinum catalyst comprising Pt and one or more additional metals selected from the group consisting of Ir, Ni, Co, Fe, Ru, Pd, Cu, and Ag, synthesized via polyol-based hydrothermal processing, and spray-coated onto as conductive substrate using a polymer based binder, as described herein.

[0263] The anodic electrolyte consisted of liquefied ammonia prepared with liquefied ammonia composition comprising one or more AnQm-type compounds and one or more supporting electrolytes with at least 20 wt.% relative to the AnQm. The cathodic compartment contained an aqueous solution of hydrochloric acid (HCl) with a concentration of at least 0.1 M as the acidic catholyte.

[0264] The anodic and cathodic compartments were separated by an ionic exchange membrane, as described in this disclosure. The membrane allowed selective transport of protons from the cathodic to the anodic compartment, maintaining ionic conductivity while preventing direct mixing of the electrolyte media. Gas–liquid separation units were installed on both compartments, and the separated gases were each passed through dedicated solid-phase ammonia adsorbent units as described in this disclosure to capture any residual ammonia vapor. Linear sweep voltammetry (LSV) was conducted in a three-electrode configuration, where an Ag / AgCl reference electrode was positioned adjacent to the working electrode at the anodic compartment, to evaluate the electrochemical performance of system. The I-V cure was recorded where the overall cell potential of 0.63 V where sufficient to drive both HER and AOR reaction, as shown in FIG.10. The system was also operated in the two-electrode configuration under galvanostatic control, using a galvanostatic current density of approximately 25 mA / cm² applied for approximately 30 minutes and the Hydrogen gas evolved at the cathode and nitrogen gas evolved at the anode were confirmed by in-line gas analysis. The faradaic efficiency for hydrogen generation exceeded 75%.

[0265] It shall be understood that different aspects of the invention can be appreciated individually, collectively, or in combination with each other. Various aspects of the invention described herein may be applied to any of the particular applications disclosed herein. TheWSGR Docket No.70778-702.601 compositions of matter disclosed herein in the composition section of the present disclosure may be utilized in the method section including methods of use and production disclosed herein, or vice versa.

[0266] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. It is not intended that the invention be limited by the specific examples provided within the specification. While the invention has been described with reference to the aforementioned specification, the descriptions and illustrations of the embodiments herein are not meant to be construed in a limiting sense. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Furthermore, it shall be understood that all aspects of the invention are not limited to the specific depictions, configurations or relative proportions set forth herein which depend upon a variety of conditions and variables. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is therefore contemplated that the invention shall also cover any such alternatives, modifications, variations or equivalents. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby. LIST OF EMBODIMENTS

[0267] The following list of embodiments of the invention are to be considered as disclosing various features of the invention, which features can be considered to be specific to the particular embodiment under which they are discussed, or which are combinable with the various other features as listed in other embodiments. Thus, simply because a feature is discussed under one particular embodiment does not necessarily limit the use of that feature to that embodiment.

[0268] Embodiment 1. A hydrogen generation apparatus comprising: a liquefaction unit which liquefies ammonia using one or more specialized compounds (AnQm.(NH3)x); an ammonia electrolyzer comprising: a cathodic part comprising: a cathode; at least a first portion of the liquefied ammonia; and at least a first primary electrolyte or a first secondary electrolyte; an anodic part comprising: an anode;WSGR Docket No.70778-702.601 at least a second portion of the liquefied ammonia; and at least a second primary electrolyte or a second secondary electrolyte; and a membrane positioned between the cathodic part and the anodic part; and a power supply connected to the cathodic part and the anodic part and configured to supply power to the ammonia electrolyzer to electrolyze the liquefied ammonia.

[0269] Embodiment 2. The hydrogen generation apparatus of embodiment 1 comprising an electrolyte mixture, wherein the electrolyte mixture comprises at least one of: the liquefied ammonia; the one or more specialized compounds (AnQm.(NH3)x); at least the first primary electrolyte or the first secondary electrolyte; or at least the second primary electrolyte or the second secondary electrolyte.

[0270] Embodiment 3. The hydrogen generation apparatus of embodiment 1, wherein the liquefaction unit comprises a liquefaction container to produce the liquefied ammonia based upon passing an ammonia gas through the one or more specialized compounds (AnQm.(NH3)x).

[0271] Embodiment 4. The hydrogen generation apparatus of embodiment 1, wherein the one or more specialized compounds (AnQm.(NH3)x) comprise at least one of: a first set of elements (A) associated with a first set of numbers (n); a second set of elements (Q) associated with a second set of numbers (m); ammonia associated with a set of molecule numbers (x).

[0272] Embodiment 5. The hydrogen generation apparatus of embodiment 4, wherein: the first set of elements comprises at least one of: Lithium (Li); Sodium (Na); Potassium (K); Rubidium (Rb); Cesium (Cs); Francium (Fr); hydrogen (H); Silver (Ag); Mercury (Hg); or an ammonium ion (NH4+); the first set of numbers (n) are from 1 to 4; andWSGR Docket No.70778-702.601 the set of molecule numbers (x) are from 0 to about 8 (i.e., x= zero when the ammonia liquefier compound does not contain ammonia and is in the form of AnQmfor ammonia liquefaction).

[0273] Embodiment 6. The hydrogen generation apparatus of embodiment 4, wherein: the second set of elements (Q) comprises at least one of: Fluorine (F); Chlorine (Cl); Bromine (Br); Iodine (I); or a multi-atomic anion; and the second set of numbers (m) are from 1 to 4.

[0274] Embodiment 7. The hydrogen generation apparatus of embodiment 6, wherein the multi-atomic anion comprises at least two atoms from groups 15, 16 or 17 of the periodic table of elements.

[0275] Embodiment 8. The hydrogen generation apparatus of embodiment 3, wherein at least one of: the liquefied ammonia is at room temperature in a range from about 59 degrees Fahrenheit to about 77 degrees Fahrenheit; or the liquefied ammonia is at a pressure close to atmospheric pressure in a range from about 1 bar to about 2 bars.

[0276] Embodiment 9. The hydrogen generation apparatus of embodiment 2, wherein the one or more specialized compounds (AnQm.(NH3)x) are used as electrolytes to increase the conductivity of the electrolyte mixture.

[0277] Embodiment 10. The hydrogen generation apparatus of embodiment 2, wherein the electrolyte mixture comprises one or more additives used as electrolytes to increase the conductivity of the electrolyte mixture.

[0278] Embodiment 11. The hydrogen generation apparatus of embodiment 10, wherein the one or more additives comprise at least one of: potassium nitrate (KNO3); sodium chloride (NaCl); sodium bromide (NaBr); potassium bromide (KBr); silver nitrate (AgNO3); lithium nitrate (LiNO3); sodium nitrate (NaNO3); ammonium iodide (NH4I); alkyl chloride (RCI); ammonium bromide (NH4Br); silver Halides (e.g., AgI, AgBr, AgCl); titanium nitrate (Ti(NO3)4); ammonium nitrate (NH4NO3); 1,3,5-trinitrobenzene (C6H5(NO2)3); 2,4,6-trinitroaniline (C6H2(NO2)3NH2); tetranitromethane (C(NO2)4); sodium nitromethanide (CH2NO2Na); ammonium nitroethane (CH5CH2NO2NH4);WSGR Docket No.70778-702.601 mercury fulminate (Hg(CNO)2); nitroguanidine (CH4N4O2); methyl nitramine (CH3N2O2); sulfanilamide (C6H8N2O2S); cyanamide (CH2N2); phthalimide (C6H4(CO)2NH); thiourea (CS(NH2)2); thiosemicarbazide (H2NNHC(S)NH2); benzamide (C6H5CONH2); phenylacetamide (C6H5CH2CONH2); cyanocetamide (CH2(CN)CONH2); ethylamine hydrochloride (C2H5NH2.HCI); diethylamine ((C2H5)2NH), lithium amide (LiNH2), ammonium amide (NH4NH2), potassium amide (KNH2), potassium hexafluorophosphate (KPF6), ammonium hexafluorophosphate (NH4PF6), sodium hexafluorophosphate (NaPF6), sodium sulfate (Na2SO4), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), potassium hydroxide (KOH), sodium nitrate (NaNO3), potassium chloride (KCl), potassium perchlorate (KClO4), sodium perchlorate (NaClO4), ammonium perchlorate (NH4ClO4), potassium silicate (K2SiO3), sodium fluoride (NaF), Sodium iodide (NaI).

[0279] Embodiment 12. The hydrogen generation apparatus of embodiment 2, wherein at least one of: the cathodic part decomposes a first portion of the electrolyte mixture based upon a first chemical reaction (e.g., a reduction reaction); the anodic part decomposes a second portion of the electrolyte mixture based upon a second chemical reaction (e.g., an oxidation reaction); the membrane allows transferring one or more ions from the anodic part to the cathodic part; or the one or more ions, wherein the one or more ions comprise at least one of: ammonium ions; or hydrogen ions.

[0280] Embodiment 13. The hydrogen generation apparatus of embodiment 12, wherein at least one of: the membrane comprises a porous material; the membrane is a selective barrier; or the membrane is a bipolar membrane.

[0281] Embodiment 14. The hydrogen generation apparatus of embodiment 1, wherein the cathodic part comprises a hydrogen evolution reaction (HER) catalyst.

[0282] Embodiment 15. The hydrogen generation apparatus of embodiment 14, wherein the hydrogen evolution reaction catalyst comprises at least one of: a metal foam; a thin metal film; carbon paper;WSGR Docket No.70778-702.601 carbon fiber; carbon felt; graphene; carbon-based nanomaterials; boron nitride; carbon cloth; or a metal catalyst, wherein the metal catalyst comprises at least one of: Platinum (Pt); Iridium (Ir); or Ruthenium (Ru).

[0283] Embodiment 16. The hydrogen generation apparatus of embodiment 1, wherein the anodic part comprises a metal catalyst.

[0284] Embodiment 17. The hydrogen generation apparatus of embodiment 16, wherein the metal catalyst comprises at least one of: Platinum (Pt); Iridium (Ir); Ruthenium (Ru); Rhodium (Rh); Iron (Fe); Cobalt (Co); Nickel (Ni); or Copper (Cu).

[0285] Embodiment 18. The hydrogen generation apparatus of embodiment 1, wherein the hydrogen generation apparatus generates at least one of: hydrogen (H2); or one or more products.

[0286] Embodiment 19. The hydrogen generation apparatus of embodiment 18, wherein the hydrogen (H2) is generated in the cathodic part.

[0287] Embodiment 20. The hydrogen generation apparatus of embodiment 18, wherein the one or more products comprise at least one of: nitrogen (N2); liquefied ammonia; or gaseous ammonia.

[0288] Embodiment 21. The hydrogen generation apparatus of embodiment 20, wherein the nitrogen (N2) is generated in the anodic part.

[0289] Embodiment 22. The hydrogen generation apparatus of embodiment 18, wherein the one or more products are reused by the hydrogen generation apparatus.

[0290] Embodiment 23. The hydrogen generation apparatus of embodiment 1, wherein the cathodic part comprises at least one of: a first portion of the membrane;WSGR Docket No.70778-702.601 a first inlet configured to receive a first portion of the liquefied ammonia; or a first outlet configured to exhaust a generated hydrogen (H2) and a first portion of an unreacted ammonia.

[0291] Embodiment 24. The hydrogen generation apparatus of embodiment 1, wherein the anodic part comprises at least one of: a second portion of the membrane; a second inlet configured to receive a second portion of the liquefied ammonia; or a second outlet configured to exhaust a generated nitrogen (N2) and a second portion of an unreacted ammonia.

[0292] Embodiment 25. The hydrogen generation apparatus of embodiment 1, wherein the hydrogen generation apparatus prevents poisoning of the cathode and the anode based upon not using a solvent.

[0293] Embodiment 26. The hydrogen generation apparatus of embodiment 8, wherein at least one of: temperature of the liquefied ammonia is regulated using a cooling device; or pressure of the liquefied ammonia is regulated using the cooling device.

[0294] Embodiment 27. A hydrogen generation system comprising: a liquefaction unit which liquefies ammonia gas using one or more specialized compounds (AnQm.(NH3)x); an ammonia electrolyzer comprising: a cathodic part comprising: a cathode; at least a first portion of the liquefied ammonia; and at least a first primary electrolyte or a first secondary electrolyte; an anodic part comprising: an anode; at least a second portion of the liquefied ammonia; and at least a second primary electrolyte or a second secondary electrolyte; and a membrane (e.g., a selective barrier, a bipolar membrane) displaced between the cathodic part and the anodic part; and a power supply connected to the cathodic part (e.g., cathode) and the anodic part (e.g., anode) and configured to supply power to the ammonia electrolyzer to electrolyze the liquefied ammonia.

[0295] Embodiment 28. The hydrogen generation system of embodiment 27, wherein theWSGR Docket No.70778-702.601 hydrogen generation system comprises a conventional storage unit configured to store the ammonia gas.

[0296] Embodiment 29. The hydrogen generation system of embodiment 28, wherein the hydrogen generation system comprises a dryer configured to dry the ammonia gas received from the conventional storage unit and to remove water inside the ammonia gas.

[0297] Embodiment 30. The hydrogen generation system of embodiment 27, wherein the hydrogen generation system comprises a first pump configured to pump the liquefied ammonia into a storage tank.

[0298] Embodiment 31. The hydrogen generation system of embodiment 30, wherein the hydrogen generation system comprises a first pump configured to pump the liquefied ammonia into a storage tank wherein the storage tank configured to store the liquefied ammonia received from the liquefaction unit.

[0299] Embodiment 32. The hydrogen generation system of embodiment 31, wherein the hydrogen generation system comprises an additive container connected to the storage tank configured to add secondary electrolytes to the liquefied ammonia.

[0300] Embodiment 33. The hydrogen generation system of embodiment 32, wherein the hydrogen generation system comprises a second pump configured to pump at least one of the liquefied ammonia, or the secondary electrolytes from the storage tank into a cooling device, wherein the cooling device is configured to maintain temperature and pressure of at least one of the liquefied ammonia, or the secondary electrolytes at room temperature in a range from about 59 degrees Fahrenheit to about 77 degrees Fahrenheit and at a pressure close to atmospheric pressure in a range from about 1 bar to about 2 bars.

[0301] Embodiment 34. The hydrogen generation system of embodiment 33, wherein the hydrogen generation system comprises a first fluid separator tank configured to separate at least one of hydrogen (H2), or ammonia gas from unreacted liquefied ammonia.

[0302] Embodiment 35. The hydrogen generation system of embodiment 34, wherein the hydrogen generation system comprises a first wet scrubber system connected to the first fluid separator tank and configured to remove the ammonia gas from the hydrogen (H2).

[0303] Embodiment 36. The hydrogen generation system of embodiment 35, wherein the hydrogen generation system comprises a first purification system connected to the first wet scrubber system and configured to purify the hydrogen (H2).

[0304] Embodiment 37. The hydrogen generation system of embodiment 36, wherein the hydrogen generation system comprises a hydrogen (H2) storage tank connected to the firstWSGR Docket No.70778-702.601 purification system and configured to store the purified hydrogen (H2).

[0305] Embodiment 38. The hydrogen generation system of embodiment 37, wherein the hydrogen generation system comprises a second fluid separator tank configured to separate nitrogen (N2) and ammonia gas from unreacted liquefied ammonia.

[0306] Embodiment 39. The hydrogen generation system of embodiment 38, wherein the hydrogen generation system comprises a second wet scrubber system connected to the second fluid separator tank and configured to remove the ammonia gas from the nitrogen (N2).

[0307] Embodiment 40. The hydrogen generation system of embodiment 39, wherein the hydrogen generation system comprises a nitrogen purification system connected to the second wet scrubber system and configured to purify the nitrogen (N2).

[0308] Embodiment 41. The hydrogen generation system of embodiment 40, wherein the hydrogen generation system comprises a nitrogen (N2) storage tank connected to the second purification system and configured to store the purified nitrogen (N2).

[0309] Embodiment 42. The hydrogen generation system of embodiment 38, wherein the unreacted liquefied ammonia separated by the first fluid separator tank and the second fluid separator tank recycles back to the liquefaction unit.

[0310] Embodiment 43. The hydrogen generation system of embodiment 39, wherein the ammonia gas separated by the first wet scrubber system and the second wet scrubber system recycles back to the liquefaction unit.

[0311] Embodiment 44. The hydrogen generation system of embodiment 39, wherein the ammonia gas separated by the first purification system and the second purification system recycles back to the liquefaction unit.

[0312] Embodiment 45. A hydrogen generation system comprising: a conventional storage unit configured to store ammonia gas; a dryer configured to dry the ammonia gas received from the conventional storage unit and to remove water inside the ammonia gas; a liquefaction unit which liquefies the ammonia gas using one or more specialized compounds (AnQm.(NH3)x); a first pump configured to pump the liquefied ammonia into a storage tank; the storage tank configured to store the liquefied ammonia received from the liquefaction unit; an additive container connected to the storage tank configured to add secondary electrolytes to the liquefied ammonia;WSGR Docket No.70778-702.601 a second pump configured to pump at least one of the liquefied ammonia, or the secondary electrolytes from the storage tank into a cooling device; the cooling device configured to maintain temperature and pressure of at least one of the liquefied ammonia, or the secondary electrolytes at room temperature in a range from about 59 degrees Fahrenheit to about 77 degrees Fahrenheit and at a pressure close to atmospheric pressure in a range from about 1 bar to about 2 bars; an ammonia electrolyzer comprising: a cathodic part comprising: a cathode; at least a first portion of the liquefied ammonia; and at least a first primary electrolyte or a first secondary electrolyte; an anodic part comprising: an anode; at least a second portion of the liquefied ammonia; and at least a second primary electrolyte or a second secondary electrolyte; and a membrane (e.g., a selective barrier, a bipolar membrane) displaced between the cathodic part and the anodic part; a power supply connected to the cathodic part (e.g., cathode) and the anodic part (e.g., anode) and configured to supply power to the ammonia electrolyzer to electrolyze the liquefied ammonia; a first fluid separator tank configured to separate at least one of hydrogen (H2), or ammonia gas from unreacted liquefied ammonia; a first wet scrubber system connected to the first fluid separator tank and configured to remove the ammonia gas from the hydrogen (H2); a first purification system connected to the first wet scrubber system and configured to purify the hydrogen (H2); a hydrogen (H2) storage tank connected to the first purification system and configured to store the purified hydrogen (H2); a second fluid separator tank configured to separate nitrogen (N2) and ammonia gas from unreacted liquefied ammonia; a second wet scrubber system connected to the second fluid separator tank and configured to remove the ammonia gas from the nitrogen (N2); a nitrogen purification system connected to the second wet scrubber system and configured to purify the nitrogen (N2); andWSGR Docket No.70778-702.601 a nitrogen (N2) storage tank connected to the second purification system and configured to store the purified nitrogen (N2).

[0313] Embodiment 46. A method for generating hydrogen (H2) and nitrogen (N2) from a liquefied ammonia, the method comprising: liquefying ammonia gas using one or more specialized compounds (AnQm.(NH3)x) in a liquefaction unit; utilizing a cooling device to cool down a mixture of the liquefied ammonia and the one or more additives to room temperature in a range from about 59 degrees Fahrenheit to about 77 degrees Fahrenheit and to reduce pressure of the mixture to a pressure close to atmospheric pressure in a range from about 1 bar to about 2 bars; and utilizing an ammonia electrolyzer to electrolyze the mixture, wherein the ammonia electrolyzer comprises: a cathodic part comprising: a cathode; at least a first portion of the liquefied ammonia; and at least a first primary electrolyte or a first secondary electrolyte; an anodic part comprising: an anode; at least a second portion of the liquefied ammonia; and at least a second primary electrolyte or a second secondary electrolyte; a membrane (e.g., a selective barrier, a bipolar membrane) displaced between the cathodic part and the anodic part; and a power supply connected to the cathodic part (e.g., cathode) and the anodic part (e.g., anode) and configured to supply power to the ammonia electrolyzer to electrolyze the liquefied ammonia.

[0314] Embodiment 47. A method for generating hydrogen (H2) and nitrogen (N2) from a liquefied ammonia, the method comprising: storing ammonia gas inside a conventional storage unit; drying the ammonia gas utilizing a dryer to dry the ammonia gas received from the conventional storage unit and to remove water inside the ammonia gas; liquefying the ammonia gas using one or more specialized compounds (AnQm.(NH3)x) in a liquefaction unit; storing the liquefied ammonia in a storage tank; adding one or more additives to the liquefied ammonia stored in the storage tank;WSGR Docket No.70778-702.601 utilizing a cooling device to cool down a mixture of the liquefied ammonia and the one or more additives to room temperature in a range from about 59 degrees Fahrenheit to about 77 degrees Fahrenheit and to reduce pressure of the mixture to a pressure close to atmospheric pressure in a range from about 1 bar to about 2 bars; utilizing an ammonia electrolyzer to electrolyze the mixture, wherein the ammonia electrolyzer comprises: a cathodic part comprising: a cathode; at least a first portion of the liquefied ammonia; and at least a first primary electrolyte or a first secondary electrolyte; an anodic part comprising: an anode; at least a second portion of the liquefied ammonia; and at least a second primary electrolyte or a second secondary electrolyte; a membrane (e.g., a selective barrier, a bipolar membrane) displaced between the cathodic part and the anodic part; a power supply connected to the cathodic part (e.g., cathode) and the anodic part (e.g., anode) and configured to supply power to the ammonia electrolyzer to electrolyze the liquefied ammonia; separating at least one of hydrogen (H2), or ammonia gas from unreacted liquefied ammonia utilizing a first fluid separator tank; removing the ammonia gas from the hydrogen (H2) utilizing a first wet scrubber system connected to the first fluid separator tank; purifying the hydrogen (H2) utilizing a first purification system connected to the first wet scrubber system; storing the purified hydrogen (H2) utilizing a hydrogen (H2) storage tank connected to the first purification system; separating at least one of nitrogen (N2), or ammonia gas from unreacted liquefied ammonia utilizing a second fluid separator tank; removing the ammonia gas from the nitrogen (N2) utilizing a second wet scrubber system connected to the second fluid separator tank; purifying the nitrogen (N2) utilizing a nitrogen purification system connected to the nitrogen wet scrubber system; andWSGR Docket No.70778-702.601 storing the purified nitrogen (N2) utilizing a nitrogen (N2) storage tank connected to the second purification system.

[0315] Embodiment 48. The hydrogen generation apparatus of embodiment 3, wherein at least one of: the liquefied ammonia is at temperature range from about 14 degrees Fahrenheit to about 180 degrees Fahrenheit and at a pressure below 10 bar pressure in a range from about 1 bar to about 10 bars.; or the liquefied ammonia is at a pressure below 10 bar and in a range range from about 1 bar to about 10 bars.

[0316] Embodiment 49. A method for generating hydrogen (H2) and nitrogen (N2) from a liquefied ammonia, the method comprising: storing ammonia gas inside a conventional storage unit; drying the ammonia gas utilizing a dryer to dry the ammonia gas received from the conventional storage unit and to remove water inside the ammonia gas; liquefying the ammonia gas using one or more specialized compounds (AnQm.(NH3)x) in a liquefaction unit; storing the liquefied ammonia in a storage tank; adding one or more additives to the liquefied ammonia stored in the storage tank; utilizing a cooling device to cool down a mixture of the liquefied ammonia and the one or more additives to temperature in range from about 14 degrees Fahrenheit to about 180 degrees Fahrenheit and at a pressure below 10 bar pressure in a range from about 1 bar to about 10 bars utilizing an ammonia electrolyzer to electrolyze the mixture, wherein the ammonia electrolyzer comprises: a cathodic part comprising: a cathode; at least a first portion of the liquefied ammonia; and at least a first primary electrolyte or a first secondary electrolyte; an anodic part comprising: an anode; at least a second portion of the liquefied ammonia; and at least a second primary electrolyte or a second secondary electrolyte; a membrane (e.g., a selective barrier, a bipolar membrane) displaced between the cathodic part and the anodic part;WSGR Docket No.70778-702.601 a power supply connected to the cathodic part (e.g., cathode) and the anodic part (e.g., anode) and configured to supply power to the ammonia electrolyzer to electrolyze the liquefied ammonia; separating at least one of hydrogen (H2), or ammonia gas from unreacted liquefied ammonia utilizing a first fluid separator tank; removing the ammonia gas from the hydrogen (H2) utilizing a first wet scrubber system connected to the first fluid separator tank; purifying the hydrogen (H2) utilizing a first purification system connected to the first wet scrubber system; storing the purified hydrogen (H2) utilizing a hydrogen (H2) storage tank connected to the first purification system; separating at least one of nitrogen (N2), or ammonia gas from unreacted liquefied ammonia utilizing a second fluid separator tank; removing the ammonia gas from the nitrogen (N2) utilizing a second wet scrubber system connected to the second fluid separator tank; purifying the nitrogen (N2) utilizing a nitrogen purification system connected to the nitrogen wet scrubber system; and storing the purified nitrogen (N2) utilizing a nitrogen (N2) storage tank connected to the second purification system.

Claims

WSGR Docket No.70778-702.601 CLAIMS WHAT IS CLAIMED IS:

1. A system comprising: (i) an ammonia preparation unit comprising a liquefier configured to stabilize ammonia in liquid state, wherein the liquefier comprises one or more compounds of the formula AnQm, wherein A is a first moiety comprising lithium (Li), sodium (Na), hydrogen (H), guanidinium (CH6N3+), ammonium (NH4+), or one or more atoms from Group 16 of periods 3, 4, 5, or 6 of the Periodic Table of Elements; Q is a second moiety comprising at least one atom selected from the group consisting of boron (B), Group 15, or Group 16 of periods 3, 4, 5, or 6, or a combination thereof, wherein, when A is guanidium (CH6N3+), Q comprises one or more atoms from Group 17; n is an integer from 1 to 4; and m is an integer from 1 to 4; and (ii) an electrochemical cell configured to convert liquid ammonia into hydrogen and nitrogen.

2. The system of claim 1, wherein the liquefier is configured to stabilize ammonia in a liquid state upon contact with ammonia, thereby forming a complex of the formula (AnQm)(NH3)y, wherein y is a number ranging from 1 to 8.

3. The system of claim 1 or 2, wherein Q comprises -BF4, -SCN, -SeCN, -NO3, -CF3SO3, - PF6, -ClO4, -C4F9SO3, -CH3CO2, -N(SO2F3)2, -NH2, -N3, or -SbF6.

4. The system of any one of claims 1 to 3, wherein the one or more of compounds of formula AnQmare selected from a group consisting of NaSCN, HSCN, NH4SCN, NH4SeCN, NaSeCN, (CH6N3)SCN (guanidinium thiocyanate), NH4NO3, NaNO3, (CH6N3)NO3(guanidinium nitrate), LiSCN, LiSeCN, NH4ClO4, NH4C4F9SO3, (CH6N3)I (guanidinium iodide), (CH6N3)BF4 (guanidinium tetrafluoroborate), NH4CH3CO2, , NH4N(SO2F3)2, (CH6N3)PF6 (guanidinium hexafluorophosphate), (CH6N3)(CF3SO3) (guanidinium trifluoromethanesulfonate), SO2(NH2)2, I2, SO2(NH2)(NC6H5), and SeO2(NH2)2.

5. The system of claim 4, wherein the one or more compounds of formula AnQm comprises sodium thiocyanate (NaSCN), ammonium thiocyanate (NH₄SCN), sulfamide (SO₂(NH₂)₂), lithium thiocyanate (LiSCN), guanidinium thiocyanate ((CH₆N₃)SCN), or guanidinium trifluoromethanesulfonate (guanidinium triflate).WSGR Docket No.70778-702.601 6. The system of claim 2, wherein the complex is present in a liquid or gel phase.

7. The system of claim 6, wherein the complex is present in a liquid or gel phase under ambient temperature and ambient pressure.

8. The system of claim 7, wherein the complex remains in liquid form across pressures in the range of about 0.001 to about 15 atm.

9. The system of claim 7 or 8, wherein the complex remains in liquid form at temperatures ranging from about -30 °C to about 120 °C.

10. The system of any one of claims 1 to 9, wherein the liquefier serves as an electrolyte.

11. The system of any one of claims 2 to 10, wherein the AnQmor (AnQm)(NH3)yis mixed with a electrolyte in the ammonia preparation unit.

12. The system of claim 11, wherein the electrolyte enhances ionic conductivity of the liquid ammonia.

13. The system of claim 11 or 12, wherein the electrolyte comprises ammonium triflate (NH₄OTf), ammonium tetrafluoroborate (NH₄BF₄), ammonium hexafluorophosphate (NH₄PF₆), or sodium triflate (NaOTf).

14. The system of claim 11 or 12, wherein the electrolyte is selected from a group consisting of ammonium halides (NH4L), wherein L is I, Br, and Cl, or multiatomic moiety comprising at least one atom from group 15, 16, and 17 of periodic table comprising CF3SO3- or PF6-.

15. The system of claim 11 or 12, wherein the electrolyte is selected from a group consisting of sodium chloride (NaCl), sodium bromide (NaBr), potassium bromide (KBr), potassium chloride (KCl), potassium nitrate (KNO₃), lithium nitrate (LiNO₃), sodium nitrate (NaNO₃), ammonium nitrate (NH₄NO₃), ammonium Chloride (NH₄Cl), ammonium Bromide (NH₄Br), ammonium iodide (NH₄I), alkyl chloride (RCl), potassium hexafluorophosphate (KPF6), ammonium hexafluorophosphate (NH4PF6), sodium hexafluorophosphate (NaPF6), ammonium triflate (NH4CF3SO3), and sodium triflate (NaCF3SO3) .

16. The system of claim 11 or 12, wherein the electrolyte comprises lithium amide (LiNH2), ammonium amide (NH4NH2), potassium amide (KNH2), sodium sulfate (Na2SO4), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), or potassium hydroxide (KOH).

17. The system of claim 11 or 12, wherein the electrolyte is selected from a group consisting of alkali metals in their cationic or metallic forms comprising Li+or Li, ammonium cation, alkylammonium cation, halide ions, alkyl amines, nitrite, nitrate, phosphate, polyphosphate, perchlorate, silicate, sulfate, carbonate, borate, or tetraalkyl ammonium.WSGR Docket No.70778-702.601 18. The system of claim 11 or 12, wherein the electrolyte is selected from a group consisting of hydrazinium chloride (N2H5Cl), hydrazinium bromide (N2H5Br), hydrazinium acetate, hydrazinium azide, and a derivative of hydrazine.

19. The system of any one of claims 1 to 18, further comprising an ammonia source unit configured to supply ammonia feedstock.

20. The system of any one of claims 1 to 19, wherein the ammonia preparation unit is further configured to deliver liquid ammonia or the complex to the electrochemical cell.

21. The system of any one of claims 1 to 20, wherein the electrochemical cell comprises an anodic compartment and a cathodic compartment.

22. The system of claim 21, wherein the anodic compartment comprises an anode and an anolyte.

23. The system of claim 22, wherein the anolyte comprises one or more electrolytes.

24. The system of claim 22 or 23, wherein liquid ammonia serves as a sole anolyte.

25. The system of any one of claims 21 to 24, wherein the anodic compartment is configured to facilitate an oxidation of ammonia through the ammonia oxidation reaction (AOR).

26. The system of claim 25, wherein the anodic compartment comprises an ammonia oxidation reaction (AOR) catalyst comprising one or more metals selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), chromium (Cr), platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh), and manganese (Mn), or a combination or an alloy thereof.

27. The system of claim 26, wherein the AOR catalyst comprises a composition comprising platinum (Pt) and one or more additional metals.

28. The system of claim 27, wherein the one or more additional metals are selected from the group consisting of iridium (Ir), cobalt (Co), iron (Fe), copper (Cu), ruthenium (Ru), rhodium (Rh), manganese (Mn), and nickel (Ni).

29. The system of claim 27, wherein the AOR catalyst is configured as a binary, ternary, multi-metallic, or heterogeneous composite.

30. The system of claim 27, wherein the AOR catalyst is present in an elemental form, an alloy, or a chemically bound form.

31. The system of claim 30, wherein the chemically bound form of the AOR catalyst comprises oxides, nitrides, phosphides, carbides, selenides, borides, hydroxides, or a combination thereof.WSGR Docket No.70778-702.601 32. The system of claim 27, wherein the AOR catalyst comprises platinum (Pt) and one or more additional metals, wherein the one or more additional metals are present at a molar ratio relative to Pt in the range of about 0.1:1 to about 10:

1.

33. The system of claim 27, wherein the AOR catalyst comprises a binary alloy of platinum (Pt) and iridium (Ir), wherein a molar ratio of Pt to Ir ranges from about 1:1 to about 10:

1.

34. The system of claim 27, wherein the AOR catalyst comprises platinum (Pt), iridium (Ir), and nickel (Ni).

35. The system of claim 34, wherein the AOR catalyst is a binary (Pt–Ni, Ir–Ni) or multi- metallic composition (Pt–Ir–Ni).

36. The system of claim 34 or 35, wherein Ni is present in the catalyst at a molar ratio of about 0.1:1 to about 10:1 relative to Pt or to the combined Pt and Ir content.

37. The system of claim 26, wherein the AOR catalyst comprises an iron-based alloy comprising one or more atoms selected from chromium (Cr), nickel (Ni), carbon (C), manganese (Mn), and optionally molybdenum (Mo).

38. The system of claim 26, wherein the AOR catalyst comprises an alloy comprising iron, nickel, chromium, and carbon.

39. The system of claim 38, wherein iron is present in the AOR catalyst at about 60 wt.% to about 90 wt.% of the AOR catalyst.

40. The system of claim 38, wherein nickel is present in the AOR catalyst at about 0.1 wt.% to about 20 wt.%.

41. The system of claim 38, wherein chromium is present in the AOR catalyst at about 8 wt.% to about 25 wt.%.

42. The system of claim 38, wherein carbon is present in the AOR catalyst at about 0.05 wt.% to about 2.1 wt.%.

43. The system of claim 26, wherein the AOR catalyst further comprises manganese (Mn) or molybdenum (Mo).

44. The system of claim 26, wherein the AOR catalyst further comprises manganese (Mn) and molybdenum (Mo).

45. The system of claim 43 or 44, wherein Mn is present in the AOR catalyst at about 0.1 wt.% to about 13.0 wt.%.

46. The system of claim 43 or 44, wherein Mo is present in the AOR catalyst at about 0.1 wt.% to about 3.0 wt.%.

47. The system of claim 26, wherein a surface of the AOR catalyst is modified to enhance catalytic activity toward ammonia oxidation.WSGR Docket No.70778-702.601 48. The system of claim 47, wherein the surface of the AOR catalyst is modified by one or more methods selected from the group consisting of mechanical polishing, sandblasting, plasma treatment, laser etching, electrochemical activation, and chemical etching.

49. The system of claim 21, wherein the cathodic compartment comprises a cathode and a catholyte.

50. The system of claim 21 or 49, wherein the cathodic compartment further comprises a hydrogen evolution reaction (HER) catalyst.

51. The system of claim 50, wherein the HER catalyst comprises at least one metal selected from a group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), platinum (Pt), palladium (Pd), iridium (Ir), ruthenium (Ru), rhodium (Rh), manganese (Mn), molybdenum (Mo), and gold (Au), or an alloy or a combination thereof.

52. The system of claim 50, wherein the HER catalyst comprises a monometallic, a bimetallic, or a trimetallic configuration, which one or more metals are integrated as an alloy, a layered structure, or a core–shell configuration.

53. The system of claim 50, wherein the HER catalyst comprises a nickel alloy comprising one or more metals selected from a group consisting of iron (Fe), ruthenium (Ru), platinum (Pt), molybdenum (Mo), manganese (Mn), cobalt (Co), copper (Cu), and silver (Ag), wherein Ni content ranges from about 30 wt.% to 99 wt.%.

54. The system of claim 50, wherein the HER catalyst comprises a platinum-based catalyst comprising Pt supported on carbon (Pt–C).

55. The system of claim 50, wherein the HER catalyst comprises platinum (Pt) and at least one or more additional metals selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), ruthenium (Ru), palladium (Pd), copper (Cu), and silver (Ag), wherein Pt content ranges from about 10 wt.% to about 90 wt.%.

56. The system of claim 21, wherein the cathodic compartment comprises an aqueous solution of one or more alkaline hydroxides comprising potassium hydroxide (KOH), sodium hydroxide (NaOH), or lithium hydroxide (LiOH).

57. The system of claim 56, wherein the cathodic compartment further comprises a membrane or a separator configured to prevent water crossover, gas mixing, or electrolyte imbalance.

58. The system of claim 49, wherein the catholyte comprises aqueous ammonia with one or more alkaline additives comprising KOH, NaOH, or LiOH.WSGR Docket No.70778-702.601 59. The system of claim 58, wherein the cathodic compartment further comprises an acidic aqueous electrolyte comprising hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), phosphoric acid (H₃PO₄), or trifluoromethanesulfonic acid (triflic acid, CF₃SO₃H).

60. The system of claim 1, wherein the system further comprises a power supply configured to be connected to the cathode and the anode.

61. The system of claim 60, wherein the power supply comprises a DC source, a battery, a potentiostat, or a programmable power supply.

62. The system of claim 21, wherein the anodic compartment and the cathodic compartment are separated by a separator.

63. The system of claim 62, wherein the separator comprises a membrane, porous diaphragm, or a multilayer laminate structure.

64. The system of claim 62, wherein the separator comprises a bipolar membrane (BPM).

65. The system of any one of claims 62 to 64, wherein the separator is configured to allow selective ionic transport for protons (H⁺) or ammonium ions (NH₄⁺).

66. The system of any one of claims 62 to 65, wherein the separator is configured to facilitate ionic conduction between the compartments while preventing or minimizing the direct crossover or mixing of the anolyte and the catholyte.

67. The system of any one of claims 62 to 66, wherein the separator is configured to maintain gas-phase separation.

68. The system of any one of claims 62 to 67, wherein the separator comprises one or more of polyethylene, polypropylene, polysulfone, polyamide, polyethersulfone (PES), polyvinylidene fluoride (PVDF), polyester, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), perfluoroethylene-propylene (FEP), ethylene-tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene (ECTFE), or polybenzimidazole (PBI).

69. The system of claim 68, wherein the separator is fabricated into a porous, a non-porous, or a reinforced membrane structure.

70. The system of any one of claims 62 to 67, wherein the separator comprises one or more of sulfonated polystyrene, sulfonated polyether ether ketone (sPEEK), sulfonated polyarylether ketone (sPAEK), sulfonated polybenzimidazole (sPBI), sulfonated polysulfone, sulfonated polyetherimide, sulfonated polyetherketone, or sulfonated polyphosphazene.

71. The system of any one of claims 62 to 67, wherein the separator comprises one or more materials selected from the group consisting of poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), or Nafion®.WSGR Docket No.70778-702.601 72. The system of any one of claims 62 to 67, wherein the separator comprises a ceramic membrane, a glass fiber filter, a porous insulating body, or a chemically stable polymer blend.

73. The system of claim 72, wherein the porous insulating body comprises or is filled with agar, zeolite, or metal oxides.

74. The system of claim 72, wherein the separator comprise a hydrophilic porous membrane or diaphragm configured to facilitate ionic conductivity.

75. The system of any one of claims 62 to 67, wherein the separator comprises a porous membrane comprising Zirfon® UPT or a polysulfone-based membrane reinforced with zirconia particles.

76. The system of claim 1, wherein the ammonia preparation unit further comprises one or more additives configured to increase the ionic conductivity of liquid ammonia.

77. The system of claim 76, wherein the one or more additives are selected from a group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), propanol (C₃H₇OH), butanol (C4H10O), dimethyl sulfoxide (C₂H₆OS), glycerol (C₃H₈O₃), acetic acid (CH₃COOH), dimethylformamide (C₃H₇NO), pyridine (C₅H₅N), ethylene glycol (C₂H₆O₂), methanol (CH₃OH), acetone (C₃H₆O), tetrahydrofuran (C₄H₈O), diethylamine (C₄H₁₁N), triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), acetonitrile (C2H3N), N-methyl-2-pyrrolidinone (C5H9NO), hexamethylphosphorous triamide (C6H19N3OP), nitromethane (CH3NO2), urea (CH4N2O), phenol (C6H6O), 2-pyrrolidone (C4H7NO), diisopropylamine (C6H15N), 1,4-dioxane (C4H8O2), and morpholine (C4H9NO).

78. The system of claim 77, wherein the one or more additives are selected from a group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), glycerol (C₃H₈O₃) or triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), and ethylene glycol ((CH₂OH)₂).

79. The system of any one of claims 76 to 78, wherein the one or more additives are further configured to tune one or more physical properties of the liquefied ammonia, wherein the one or more physical properties comprise boiling point, vapor pressure, viscosity, solubility, or thermal stability.

80. The system of claim 76, wherein the one or more additives are selected from group comprises 1,3,5-trinitrobenzene (C₆H₃(NO₂)₃), 2,4,6-trinitroaniline (C₆H₂(NO₂)₃NH₂), tetranitromethane (C(NO₂)₄), sodium nitromethanide (CH₂NO₂Na), ammonium nitroethane (CH₃CH₂NO₂NH₄), , nitroguanidine (CH₄N₄O₂), methyl nitramine (CH₃N₂O₂), sulfanilamide (C₆H₈N₂O₂S), cyanamide (CH₂N₂), phthalimide (C₆H₄(CO)₂NH), thiourea (CS(NH₂)₂), thiosemicarbazide (H₂NNHC(S)NH₂), benzamide (C₆H₅CONH₂), phenylacetamideWSGR Docket No.70778-702.601 (C₆H₅CH₂CONH₂), cyanocetamide (CH₂(CN)CONH₂), ethylamine hydrochloride (C₂H₅NH₂·HCl), and diethylamine ((C₂H₅)₂NH).

81. The system of any one of claims 75 to 80, wherein the one or more additives remain inert with both the cathodic and anodic compartment.

82. The system of any one of claims 75 to 81, wherein the one or more additives are configured to modify the vapor pressure of ammonia by about 5% to about 40% when in contact with ammonia.

83. The system of any one of claims 75 to 82, wherein the one or more additives are configured to modify the ionic conductivity of liquefied ammonia by about 2 to about 100 times when in contact with ammonia.

84. The system of claim 1, further comprising a dryer configured to remove moisture from ammonia feedstock prior to introduction into the ammonia conditioning unit.

85. The system of claim 1, wherein the electrochemical cell is integrated with one or more downstream gas management units configured to isolate product gases and recover unreacted ammonia.

86. The system of claim 84, wherein the one or more downstream gas management units comprise gas–liquid separation modules, ammonia-selective adsorbent units, and gas purification components for hydrogen and nitrogen, or tailored to the specific operating configuration (e.g., flow-through or non-flow).

87. The system of claim 1, further comprising an adsorbent unit configured to utilize one or more compounds of formula AnQm as an adsorbent medium.

88. The system of claim 87, wherein the adsorbent medium comprises one or more compositions comprising at least one of lithium thiocyanate (LiSCN), ammonium thiocyanate (NH₄SCN), or sulfamide (NH₂SO₂NH₂).

89. The system of claim 1, wherein the electrochemical cell is configured for continuous-flow or batch operation.

90. The system of claim 1, wherein the system comprises more than one electrochemical cell, wherein one or more electrochemical cells in the system are arranged in series or parallel configurations.

91. The system of claim 1, wherein the electrochemical cell further comprises a sealing gasket, an electrical terminal, a flow port, a thermal regulation component, or a pressure or flow control element.

92. The system of claim 1, further comprising a downstream gas separation unit configured to purify hydrogen produced in the electrochemical cell.WSGR Docket No.70778-702.601 93. The system of claim 1, further comprising a gas–liquid separator that is positioned downstream of the anode outlet configured to isolate the nitrogen and the ammonia from liquid phase.

94. The system of claim 87, further comprising a second adsorbent unit configured to selectively capture residual ammonia.

95. The system of claim 1, further comprising a downstream gas–liquid separation and a multi-stage adsorbent-based purification configured to recover ammonia and isolate the hydrogen and nitrogen.

96. A method comprising: (i) contacting ammonia with a liquefier comprising one or more compounds of the formula AnQmto form a liquefied ammonia, wherein A is a first moiety comprising lithium (Li), sodium (Na), hydrogen (H), guanidinium (CH6N3+), ammonium (NH4+), or one or more atoms from Group 16 of periods 3, 4, 5, and 6 of the Periodic Table of Elements; Q is a second moiety comprising at least one atom from boron (B), Group 15, or Group 16 of periods 3, 4, 5, and 6, or a combination thereof, wherein, when A is guanidium (CH6N3+), Q comprises one or more atoms from Group 17; n is an integer from 1 to 4; and m is an integer from 1 to 4; (ii) providing the liquefied ammonia to an electrochemical cell; and (iii) applying an electric potential across the electrochemical cell to convert the ammonia into hydrogen and nitrogen.

97. The method of claim 96, further comprising generating (AnQm)(NH3)y by storing the ammonia in a liquid state, wherein y is a number ranging from 1 to 8.

98. The method of claim 96 or 97, wherein Q comprises -BF4, -SCN, -SeCN, -NO3, -CF3SO3, -PF6, -ClO4, -C4F9SO3, -CH3CO2, -N(SO2F3)2, -NH2, -N3, or -SbF6.

99. The method of any one of claims 96 to 98, wherein the one or more of compounds of formula AnQm are selected from a group consisting of NaSCN, HSCN, NH4SCN, NH4SeCN, NaSeCN, (CH6N3)SCN (guanidinium thiocyanate), NH4NO3, NaNO3, (CH6N3)NO3 (guanidinium nitrate), LiSCN, LiSeCN, NH4ClO4, NH4C4F9SO3, (CH6N3)I (guanidinium iodide), (CH6N3)BF4 (guanidinium tetrafluoroborate), NH4CH3CO2, NH4N(SO2F3)2, (CH6N3)PF6WSGR Docket No.70778-702.601 (guanidinium hexafluorophosphate), (CH6N3)(CF3SO3) (guanidinium trifluoromethanesulfonate), SO2(NH2)2, I2, SO2(NH2)(NC6H5), and SeO2(NH2)2.

100. The method of claim 99, wherein the one or more compounds of formula AnQm comprises sodium thiocyanate (NaSCN), ammonium thiocyanate (NH₄SCN), sulfamide (SO₂(NH₂)₂), lithium thiocyanate (LiSCN), guanidinium thiocyanate ((CH₆N₃)SCN), or guanidinium trifluoromethanesulfonate (guanidinium triflate).

101. The method of claim 97, wherein the complex is present in a liquid or gel 102. The method of claim 101, wherein the complex is present in a liquid or gel phase under ambient temperature and ambient pressure.

103. The method of claim 102, wherein the complex remains in liquid form across pressures in the range of about 0.001 to about 15 atm.

104. The method of claim 101 or 102, wherein the complex remains in liquid form at temperatures ranging from about -30 °C to about 120 °C.

105. The method of any one of claims 96 to 104, wherein the liquefier serves as an electrolyte.

106. The method of claim 96, further comprising mixing the AnQmor (AnQm)(NH3)ywith a supporting electrolyte in the ammonia preparation unit.

107. The method of claim 96, wherein the electrolyte enhances ionic conductivity of the liquid ammonia.

108. The method of claim 106 or 107, wherein the electrolyte comprises ammonium triflate (NH₄OTf), ammonium tetrafluoroborate (NH₄BF₄), ammonium hexafluorophosphate (NH₄PF₆), or sodium triflate (NaOTf).

109. The method of claim 106 or 107, wherein the electrolyte is selected from a group consisting of ammonium halides (NH4L), wherein L is I, Br, and Cl, or multiatomic moiety comprising at least one atom from group 15, 16, and 17 of periodic table comprising CF3SO3- or PF6-.

110. The method of claim 106 or 107, wherein the electrolyte is selected from a group consisting of sodium chloride (NaCl), sodium bromide (NaBr), potassium bromide (KBr), potassium chloride (KCl), potassium nitrate (KNO₃), lithium nitrate (LiNO₃), sodium nitrate (NaNO₃), ammonium nitrate (NH₄NO₃), ammonium Chloride (NH₄Cl), ammonium Bromide (NH₄Br), ammonium iodide (NH₄I), alkyl chloride (RCl), potassium hexafluorophosphate (KPF6), ammonium hexafluorophosphate (NH4PF6), sodium hexafluorophosphate (NaPF6), ammonium triflate (NH4CF3SO3), and sodium triflate (NaCF3SO3).WSGR Docket No.70778-702.601 111. The method of claim 106 or 107, wherein the electrolyte comprises lithium amide (LiNH2), ammonium amide (NH4NH2), potassium amide (KNH2), sodium sulfate (Na2SO4), potassium carbonate (K2CO3), potassium bicarbonate (KHCO3), or potassium hydroxide (KOH).

112. The method of claim 102 or 107, wherein the electrolyte is selected from a group consisting of alkali metals in their cationic or metallic forms comprising Li+or Li, ammonium cation, alkylammonium cation, halide ions, alkyl amines, nitrite, nitrate, phosphate, polyphosphate, perchlorate, silicate, sulfate, carbonate, borate, or tetraalkyl ammonium.

113. The method of claim 106 or 107, wherein the electrolyte is selected from a group consisting of hydrazinium chloride (N2H5Cl), hydrazinium bromide (N2H5Br), hydrazinium acetate, hydrazinium azide, and a derivative of hydrazine.

114. The method of claim 96, further comprising supplying ammonia feedstock using an ammonia source unit.

115. The method of any one of claims 96 to 114, wherein the electrochemical cell comprises an anodic compartment and a cathodic compartment.

116. The method of claim 115, wherein the anodic compartment comprises an anode and an anolyte.

117. The method of claim 116, wherein the anolyte comprises one or more electrolytes.

118. The method of claim 116 or 117, wherein the liquefied ammonia serves as a sole anolyte.

119. The method of any one of claims 116 to 118, wherein the anodic compartment facilitates an oxidation of ammonia through the ammonia oxidation reaction (AOR).

120. The method of claim 119, wherein the anodic compartment comprises an ammonia oxidation reaction (AOR) catalyst comprising one or more metals selected from the group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), chromium (Cr), platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh), and manganese (Mn), or a combination or an alloy thereof.

121. The method of claim 120, wherein the AOR catalyst comprises a composition comprising platinum (Pt) and one or more additional metals.

122. The method of claim 121, wherein the one or more additional metals are selected from a group consisting of iridium (Ir), cobalt (Co), iron (Fe), copper (Cu), ruthenium (Ru), rhodium (Rh), manganese (Mn), and nickel (Ni).

123. The method of claim 120, wherein the AOR catalyst is configured as a binary, ternary, multi-metallic, or heterogeneous composite.

124. The method of claim 120, wherein the AOR catalyst are present in an elemental form, an alloy, or a chemically bound form.WSGR Docket No.70778-702.601 125. The method of claim 124, wherein the chemically bound form comprises oxides, nitrides, phosphides, carbides, selenides, borides, hydroxides, or a combination thereof.

126. The method of claim 120, wherein the AOR catalyst comprises platinum (Pt) and one or more additional metals, wherein the one or more additional metals are present at a molar ratio relative to Pt in the range of about 0.1:1 to about 10:

1.

127. The method of claim 120, wherein the AOR catalyst comprises a binary alloy of platinum (Pt) and iridium (Ir), wherein a molar ratio of Pt to Ir ranges from about 1:1 to about 10:

1.

128. The method of claim 120, wherein the AOR catalyst comprises platinum (Pt), iridium (Ir), and nickel (Ni).

129. The method of claim 128, wherein the AOR catalyst is a binary (Pt–Ni, Ir–Ni) or multi- metallic composition (Pt–Ir–Ni).

130. The method of claim 128 or 129, wherein Ni is present in the catalyst at a molar ratio of about 0.1:1 to about 10:1 relative to Pt or to the combined Pt and Ir content.

131. The method of claim 120, wherein the AOR catalyst comprises an iron-based alloy comprising one or more selected from chromium (Cr), nickel (Ni), carbon (C), manganese (Mn), and optionally molybdenum (Mo).

132. The method of claim 120, wherein the AOR catalyst comprises an alloy comprising iron, nickel, chromium, and carbon.

133. The method of claim 132, wherein iron is present in the AOR catalyst at about 60 wt.% to about 90 wt.% of the AOR catalyst.

134. The method of claim 132 or 133, wherein nickel is present in the AOR catalyst at about 0.1 wt.% to about 20 wt.%.

135. The method of any one of claims 132 to 134, wherein chromium is present in the AOR catalyst at about 8 wt.% to about 25 wt.%.

136. The method of any one of claims 132 to 135, wherein carbon is present in the AOR catalyst at about 0.05 wt.% to about 2.1 wt.%.

137. The method of claim 120, wherein the AOR catalyst further comprises manganese (Mn) or molybdenum (Mo).

138. The method of claim 120, wherein the AOR catalyst further comprises manganese (Mn) and molybdenum (Mo).

139. The method of claim 137 or 138, wherein Mn is present in the AOR catalyst at about 0.1 wt.% to about 13.0 wt.%.

140. The method of claim 137 or 138, wherein Mo is present in the AOR catalyst at about 0.1 wt.% to about 3.0 wt.%.WSGR Docket No.70778-702.601 141. The method of claim 120, wherein a surface of the AOR catalyst is modified to enhance catalytic activity toward ammonia oxidation.

142. The method of claim 141, wherein the surface of the AOR catalyst is modified by one or more methods selected from the group consisting of mechanical polishing, sandblasting, plasma treatment, laser etching, electrochemical activation, and chemical etching.

143. The method of claim 114, wherein the cathodic compartment comprises a cathode and a catholyte.

144. The method of claim 143, wherein the cathodic compartment further comprises a hydrogen evolution reaction (HER) catalyst.

145. The method of claim 144, wherein the HER catalyst comprises at least one metal selected from a group consisting of nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), platinum (Pt), palladium (Pd), iridium (Ir), ruthenium (Ru), rhodium (Rh), manganese (Mn), molybdenum (Mo), and gold (Au), or an alloy or a combination thereof.

146. The method of claim 144, wherein the HER catalyst comprises a monometallic, a bimetallic, or a trimetallic configuration, which one or more metals are integrated as an alloy, a layered structure, or a core–shell configuration.

147. The method of claim 144, wherein the HER catalyst comprises a nickel alloy comprising one or more metals selected from a group consisting of iron (Fe), ruthenium (Ru), platinum (Pt), molybdenum (Mo), manganese (Mn), cobalt (Co), copper (Cu), and silver (Ag), wherein Ni content ranges from about 30 wt.% to 99 wt.%.

148. The method of claim 144, wherein the HER catalyst comprises a platinum-based catalyst comprising Pt supported on carbon (Pt–C).

149. The method of claim 144, wherein the HER catalyst comprises platinum (Pt) and at least one or more additional metals selected from a group consisting of nickel (Ni), cobalt (Co), iron (Fe), ruthenium (Ru), palladium (Pd), copper (Cu), and silver (Ag), wherein Pt content ranges from about 10 wt.% to about 90 wt.%.

150. The method of claim 144, wherein the cathodic compartment comprises an aqueous solution of one or more alkaline hydroxides comprising potassium hydroxide (KOH), sodium hydroxide (NaOH), or lithium hydroxide (LiOH).

151. The method of claim 96, further comprising preventing water crossover, gas mixing, or electrolyte imbalance by a membrane or a separator located in the cathodic compartment.

152. The method of claim 151, wherein the cathodic compartment further comprises the catholyte comprising aqueous ammonia with one or more alkaline additives comprising KOH, NaOH, or LiOH.WSGR Docket No.70778-702.601 153. The method of claim 151, wherein the cathodic compartment further comprises an acidic aqueous electrolyte comprising hydrochloric acid (HCl), sulfuric acid (H₂SO₄), nitric acid (HNO₃), phosphoric acid (H₃PO₄), or trifluoromethanesulfonic acid (triflic acid, CF₃SO₃H).

154. The method of claim 151, wherein the anodic compartment and the cathodic compartment are separated by a separator.

155. The method of claim 154, wherein the separator comprises a membrane, porous diaphragm, or a multilayer laminate structure.

156. The method of claim 154, wherein the separator comprises a bipolar membrane (BPM).

157. The method of any one of claims 154 to 156, wherein the separator allows selective ionic transport for protons (H⁺) or ammonium ions (NH₄⁺).

158. The method of any one of claims 154 to 157, wherein the separator facilitates ionic conduction between the compartments while preventing or minimizing the direct crossover or mixing of the anolyte and the catholyte.

159. The method of any one of claims 154 to 158, wherein the separator maintains gas-phase separation, allowing for independent evolution and collection of hydrogen at the cathode and nitrogen at the anode without cross-contamination or back-diffusion of reactive species.

160. The method of any one of claims 154 to 159, wherein the separator comprises one or more of polyethylene, polypropylene, polysulfone, polyamide, polyethersulfone (PES), polyvinylidene fluoride (PVDF), polyester, polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), perfluoroethylene-propylene (FEP), ethylene-tetrafluoroethylene (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene (ECTFE), or polybenzimidazole (PBI).

161. The method of claim 160, wherein the separator is fabricated into a porous, a non-porous, or a reinforced membrane structure.

162. The method of any one of claims 154 to 159, wherein the separator comprises one or more of sulfonated polystyrene, sulfonated polyether ether ketone (sPEEK), sulfonated polyarylether ketone (sPAEK), sulfonated polybenzimidazole (sPBI), sulfonated polysulfone, sulfonated polyetherimide, sulfonated polyetherketone, or sulfonated polyphosphazene.

163. The method of any one of claims 154 to 159, wherein the separator comprises one or more materials selected from the group consisting of poly(perfluorosulfonic acid), poly(perfluorocarboxylic acid), or Nafion®.

164. The method of any one of claims 154 to 159, wherein the separator comprises a ceramic membrane, a glass fiber filter, a porous insulating body, or a chemically stable polymer blend.WSGR Docket No.70778-702.601 165. The method of claim 164, wherein the porous insulating body comprises or is filled with agar, zeolite, or metal oxides.

166. The method of claim 164, wherein the separator comprise a hydrophilic porous membrane or diaphragm configured to facilitate ionic conductivity.

167. The method of any one of claims 154 to 159, wherein the separator comprises a porous membrane comprising Zirfon® UPT or a polysulfone-based membrane reinforced with zirconia particles.

168. The method of claim 96, further comprising increasing an ionic conductivity of liquefied ammonia using one or more additives in the ammonia preparation unit.

169. The method of claim 168, wherein the one or more additives are selected from a group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), propanol (C₃H₇OH), butanol (C4H10O), dimethyl sulfoxide (C₂H₆OS), glycerol (C₃H₈O₃), acetic acid (CH₃COOH), dimethylformamide (C₃H₇NO), pyridine (C₅H₅N), ethylene glycol (C₂H₆O₂), methanol (CH₃OH), acetone (C₃H₆O), tetrahydrofuran (C₄H₈O), diethylamine (C₄H₁₁N), triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), acetonitrile (C2H3N), N-methyl-2-pyrrolidinone (C5H9NO), hexamethylphosphorous triamide (C6H19N3OP), nitromethane (CH3NO2), urea (CH4N2O), phenol (C6H6O), 2-pyrrolidone (C4H7NO), diisopropylamine (C6H15N), 1,4-dioxane (C4H8O2), and morpholine (C4H9NO).

170. The method of claim 169, wherein the one or more additives are selected from a group consisting of water (H₂O), ethanol (C₂H₅OH), isopropanol (C₃H₇OH), glycerol (C₃H₈O₃) or triethylamine (C₆H₁₅N), propylene carbonate (C4H6O3), ethylene carbonate (C3H4O3), propylene glycol (C3H8O2), and ethylene glycol ((CH₂OH)₂).

171. The method of any one of claims 168 to 170, wherein the one or more additives are configured to function as a supporting electrolyte.

172. The method of claim 171, wherein the one or more additives are selected from group comprises 1,3,5-trinitrobenzene (C₆H₃(NO₂)₃), 2,4,6-trinitroaniline (C₆H₂(NO₂)₃NH₂), tetranitromethane (C(NO₂)₄), sodium nitromethanide (CH₂NO₂Na), ammonium nitroethane (CH₃CH₂NO₂NH₄), , nitroguanidine (CH₄N₄O₂), methyl nitramine (CH₃N₂O₂), sulfanilamide (C₆H₈N₂O₂S), cyanamide (CH₂N₂), phthalimide (C₆H₄(CO)₂NH), thiourea (CS(NH₂)₂), thiosemicarbazide (H₂NNHC(S)NH₂), benzamide (C₆H₅CONH₂), phenylacetamide (C₆H₅CH₂CONH₂), cyanocetamide (CH₂(CN)CONH₂), ethylamine hydrochloride (C₂H₅NH₂·HCl), and diethylamine ((C₂H₅)₂NH).

173. The method of claim 171, wherein the one or more additives remain inert with both the cathodic and anodic compartment.WSGR Docket No.70778-702.601 174. The method of claim 171, wherein the one or more additives modify the vapor pressure of ammonia by about 5% to about 40% when in contact with ammonia.

175. The method of claim 171, wherein the one or more additives modify the ionic conductivity of liquefied ammonia by about 2 to about 100 times when in contact with ammonia.

176. The method of claim 96, further comprising removing moisture from ammonia feedstock prior to introduction into the ammonia conditioning unit using a dryer.

177. The method of claim 96, further comprising isolating product gases and recovering unreacted ammonia using one or more downstream gas management units placed in the electrochemical cell.

178. The method of claim 177, wherein the one or more downstream gas management units comprise gas–liquid separation modules, ammonia-selective adsorbent units, and gas purification components for hydrogen and nitrogen, or tailored to the specific operating configuration (e.g., flow-through or non-flow).

179. The method of claim 96, further comprising utilizing one or more compounds of formula AnQmas an adsorbent medium.

180. The method of claim 179, wherein the adsorbent medium comprises one or more compositions comprising at least one of lithium thiocyanate (LiSCN), ammonium thiocyanate (NH₄SCN), or sulfamide (NH₂SO₂NH₂).

181. The method of claim 96, wherein the electrochemical cell is configured for continuous- flow or batch operation.

182. The method of claim 96, wherein the electrochemical cell further comprises a sealing gasket, an electrical terminal, a flow port, a thermal regulation component, or a pressure or flow control element.

183. The method of claim 96, further comprising purifying the hydrogen using a downstream gas separation unit.

184. The method of claim 96, further comprising isolating the nitrogen and the ammonia from liquid phase using a gas–liquid separator that is positioned downstream of the anode outlet.

185. The method of claim 96, further comprising selectively capturing residual ammonia using a second adsorbent unit.

186. The method of claim 96, further comprising recovering ammonia and isolating the hydrogen and nitrogen using a downstream gas–liquid separation and a multi-stage adsorbent- based purification.

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