Cost-effective ni-RH bi-functional catalysts with enhanced stability for alcohol aqueous phase reforming

Abstract

Herein disclosed is a catalyst for alcohol aqueous phase reforming, the catalyst comprising: a support comprising at least one layer of a transition metal dichalcogenide; and transition metal particles dispersed on a surface of the support, wherein the transition metal particles comprise nickel particles and at least one noble metal particles, and wherein the nickel particles and the at least one noble metal particles are dispersed in proximity of vacancies residing in the at least one layer of the transition metal dichalcogenide. A method for forming the catalyst, and an alcohol aqueous phase reforming process, are also disclosed.

Description

COST-EFFECTIVE Nl-RH Bl-FUNCTIONAL CATALYSTS WITH ENHANCED STABILITY FOR ALCOHOL AQUEOUS PHASE REFORMINGCross-Reference to Related Application

[0001] This application claims the benefit of priority of Singapore Patent Application No. 10202500762V, filed 24 March 2025, the content of it being hereby incorporated by reference in its entirety for all purposes.Technical Field

[0002] The present disclosure relates to a catalyst for alcohol aqueous phase reforming. The present disclosure also relates to a method for forming the catalyst and an alcohol aqueous phase reforming process.Background

[0003] Hydrogen production for fuel cells remains a critical challenge. Most hydrogen is currently produced through energy-intensive steam reforming of hydrocarbons, requiring high and consistent temperatures, which leads to significant energy loss. Moreover, the catalysts used in these processes often degrade rapidly at high temperatures due to carbon deposition, sintering, and poisoning, shortening their operational lifespan. While water electrolysis using renewable energy sources (wind, hydro, solar) may be a cleaner alternative, its high cost and limited scalability hinder widespread adoption.

[0004] An environmentally friendly alternative, known as aqueous phase reforming (APR) of biomass-derived materials, was developed. This approach may contribute to sustainability, as it enables in-situ CO2capture, making the process nearly carbon-neutral. Among available feedstocks, ethanol may be a more environmentally friendly option, primarily derived from renewable sources like biomass or sugar fermentation. It is safer, less toxic, and less flammable, making it easier to handle, store, and transport compared to other alternatives like methanol. In other words, aqueous phase reforming (APR) of biomass-derived ethanol offers a more sustainable and eco-friendlier alternative, as it enables in-situ CO2capture, creating a near-carbon-neutral cycle.

[0005] However, ethanol APR may not be without challenges, due to the difficult of cleaving C-C bonds, which tend to reduce catalytic efficiency and hydrogen yield. Furthermore, any presence of C-0 bond and its cleavage may render the formation of undesirable by-products like acetaldehyde, acetic acid, and alkanes, further complicating the process. These by-products may consume hydrogen and valuable reactants, and also reduce selectivity for the desired hydrogen output.

[0006] There is thus a need to provide for a solution that addresses one or more of the limitations mentioned above.Summary

[0007] In a first aspect, there is provided for a catalyst for alcohol aqueous phase reforming, the catalyst comprising:a support comprising at least one layer of a transition metal dichalcogenide; and transition metal particles dispersed on a surface of the support,wherein the transition metal particles comprise nickel particles and at least one noble metal particles, andwherein the nickel particles and the at least one noble metal particles are dispersed in proximity of vacancies residing in the at least one layer of the transition metal dichalcogenide.

[0008] In another aspect, there is provided for a method for forming the catalyst of various embodiments of the first aspect, the method comprising:providing a support comprising at least one layer of a transition metal dichalcogenide; andforming the transition metal particles dispersed on a surface of the support.

[0009] In another aspect, there is provided for an alcohol aqueous phase reforming process, the process comprising:providing the catalyst of various embodiments of the first aspect in a reactor; introducing an alcohol and an aqueous alkaline into the reactor to form a reaction mixture; andheating the reaction mixture to generate hydrogen gas and carbon dioxide.Brief Description of the Drawings

[0010] The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the present disclosure. In the following description, various embodiments of the present disclosure are described with reference to the following drawings, in which:

[0011] FIG. 1A is a TEM image of the MoS2having 15 to 20 layers. Scale bar denotes 20 nm.

[0012] FIG. IB is a TEM image of the MoS2having 5 to 8 layers. Scale bar denotes 20 nm.

[0013] FIG. 1C is a TEM image of the MoS2having 1 to 2 layers. Scale bar denotes 20 nm.

[0014] FIG. ID shows XRD patterns of the MoS2with different layers.

[0015] FIG. IE is a TEM image of a single layer MoS2supported Rh (Rh@MoS2-ML) catalyst. “ML” denotes monolayer.

[0016] FIG. IF is a TEM image of a single layer MoS2supported Ni (Ni@MoS2-ML) catalyst. “ML” denotes monolayer.

[0017] FIG. 2A is a table showing comparison of the present catalyst M@MoS2 against traditional and commercial catalysts in ethanol aqueous phase reforming performance testing, wherein M denotes for one or more transition metal.aH2selectivity in the gas products was measured after the in-situ capture of CO2.btested use KOH as electrolyte, pH = 14. M denotes for a transition metal and / or at least one noble metal of the transition metal particles of the present disclosure. For non-limiting examples, M may be Rh and / or Ni.

[0018] FIG. 2B is a table comparing the H2yield of catalysts of the present disclosure (demarcated by the dotted line rectangle) against others. H2yield can be seen to increase 30 times when the solvent changed to KOH and / or K2CO3solution.

[0019] FIG. 2C compares the H2production rate and selectivity of a catalyst of the present disclosure (demarcated by the dotted line rectangle) against others. It can be seen that hydrogen yield was 2 times higher for the present catalyst.

[0020] FIG. 3 is a table comparing the H2yield, purity and catalyst structure of the present catalyst against others.

[0021] FIG. 4 schematically illustrates a vacancy-rich, transition metal dichalcogenide supported catalyst of the present disclosure for alcohol aqueous phase reforming. As shown, a single layer of MoS2support comprises a lattice containing surface vacancies (e.g., sulfur and / or molybdenum vacancies), forming a vacancy-rich MoXnstructure (X denotes a chalcogen; n denotes an integer (e.g., 2)). Transition-metal particles, represented as nickel or rhodium particles, are anchored at or in proximity to these vacancies, which stabilize the metal particles and inhibit aggregation. During operation, an alcohol reactant (e.g., ethanol, C2H5OH) is adsorbed and activated at the metalsupport interface, where catalytic reforming reactions occur. The cooperative interaction between the transition-metal particles and the vacancy-rich MoS2support facilitates alcohol conversion and promotes the generation of hydrogen (H2), while the vacancies provide anchoring sites that enhance metal dispersion and catalytic stability.

[0022] FIG. 5 illustrates a liquid-phase alcohol aqueous reforming process integrated with in-situ CO2capture and electrolyte regeneration, wherein the upper schematic shows ethanol introduced into an aqueous potassium carbonate medium in the presence of a catalyst of the present disclosure to generate hydrogen and carbon dioxide, with the CO2being immediately absorbed to form potassium bicarbonate, enabling simultaneous hydrogen production and CO2capture followed by gas–liquid separation and regeneration of the electrolyte for recycling in a closed-loop system. The lower schematic depicts reaction pathways during ethanol aqueous phase reforming, including alcohol dehydrogenation, C-C bond cleavage, and water-gas shift reactions, highlighting the role of metal active sites and oxygen vacancies in facilitating water activation and hydrogen generation, while indicating competing side reactions such as methanation, with the integrated CO2capture shifting reaction equilibria toward enhanced hydrogen yield, selectivity, and process efficiency.Detailed Description

[0023] The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the present disclosure may be practised.

[0024] Features that are described in the context of an embodiment may correspondingly be applicable to the same or similar features in the other embodiments.Features that are described in the context of an embodiment may correspondingly be applicable to the other embodiments, even if not explicitly described in these other embodiments. Furthermore, additions and / or combinations and / or alternatives as described for a feature in the context of an embodiment may correspondingly be applicable to the same or similar feature in the other embodiments.

[0025] The present disclosure relates to a catalyst. The catalyst can be suitable for use in alcohol aqueous phase reforming. The catalyst may be a bi-functional catalyst in that it can perform two distinct but cooperating catalytic activity that are physically and electronically differentiated, yet synergistically coupled. For example, the catalyst may comprise two transition metals, wherein one may provide reforming activity and the other may providing electronic stabilization and hydrogen-selective catalysis. For example, the catalyst may comprise nickel and at least one noble metal (e.g., rhodium), wherein nickel and the at least one noble metal, such as rhodium, may perform distinct catalytic roles, wherein nickel predominantly facilitates alcohol reforming and C-C bond cleavage, while the at least one noble metal, such as rhodium, promotes hydrogen-related reactions and stabilizes nickel via electron transfer in alkaline environments, the two catalytic activities may be cooperatively enabled by a vacancy-rich support (e.g., a MoS2support).

[0026] Advantageously, in other words, the present catalyst is advantageous in that the catalyst can significantly enhance both catalytic activity and stability. The strong interaction between the transition metals (e.g., one transition metal and one noble metal), such as Rh and Ni, may facilitate electron transfer, stabilizing Ni in harsh alkaline environments (compared to pure Ni catalysts which are susceptible to degrade in such environments).

[0027] Also, the catalyst is synthesized through an improved hydrothermal method, which confers a 50% increase in activity compared to traditional catalysts.

[0028] Additionally, alcohol aqueous phase reforming (APR) processes involving the catalyst allows KOH to be replaced with K2CO3, advantageously offering CO2adsorption, allowing for easier regeneration and recycling. This substitution improves the economic viability and sustainability of the process by reducing the need for large amounts of electrolyte. This approach not only integrates alcohol (e..g, ethanol) APR and CO2 capture efficiently but also offers a solution to long-standing traditional issuesof catalyst degradation and poor hydrogen yield. The catalyst and method offer significant potential for advancing the field of catalysis and promoting greener, more sustainable hydrogen production, contributing to environmental preservation and the development of green energy technologies.

[0029] Understandably, it follows that a method for forming the catalyst, and an alcohol aqueous phase reforming process involving such catalyst, have aforesaid advantages.

[0030] Details of various embodiments of the catalyst, the method for forming the catalyst, and the alcohol aqueous phase reforming process, advantages associated with the various embodiments are now described below. Where advantages of the embodiments and features are already demonstrated in one or more examples below, they shall not be reiterated for brevity.

[0031] In the present disclosure, there is provided for a catalyst for alcohol aqueous phase reforming. In various embodiments, the catalyst may comprise: a support comprising at least one layer of a transition metal dichalcogenide; and transition metal particles dispersed on a surface of the support, wherein the transition metal particles may comprise nickel particles and at least one noble metal particles (e.g., rhodium particles), and wherein the nickel particles and the at least one noble metal particles (e.g., rhodium particles) may be dispersed in proximity of vacancies residing in the at least one layer of the transition metal dichalcogenide. In various embodiments, the transition metal particles may comprise nickel and at least one noble metal (e.g., rhodium particles). Single noble metal may be catalytically effective, but their high cost may motivate replacement with non-noble metal as a traditional means. Also, a transition metal, e.g., nickel, may provide a desirable performance for ethanol reforming but may be prone to oxidative deactivation in the liquid phase. To circumvent these issues, a small amount of noble metal, such as rhodium or other noble metals with similar electronic properties, may be introduced as an electronic promoter to stabilize the transition metal, such as nickel, against oxidation. In other words, in various embodiments, the transition metal particles may comprise nickel particles and at least one noble metal. In various embodiments, the at least one noble metal may comprise rhodium, gold, platinum, palladium, iridium, ruthenium, and / or osmium. In the context of the present disclosure, a noble metal may be a metal with high resistance to oxidationand corrosion, and may include, without being limited to, rhodium, gold, platinum, palladium, iridium, ruthenium, and / or osmium.

[0032] Advantageously, the catalyst offers strong metal-support interaction via vacancy anchoring, improving dispersion and suppressing metal sintering under harsh alkaline APR conditions. The catalyst includes a vacancy-rich support, which can enhance active site density and facilitate catalytic reactions involving C-C bond cleavage and water activation. Such catalyst can enable synergistic bimetallic (transition metals) behaviour, improving hydrogen formation rate and selectivity compared to monometallic catalyst.

[0033] In various embodiments, the transition metal dichalcogenide may comprise molybdenum disulfide, and / or wherein the at least one noble metal particles comprise rhodium, gold, platinum, palladium, iridium, ruthenium, and / or osmium. The support, such as the MoS2support, is not merely a passive support. The support can anchor the transition metal particles, such as Ni and Rh near vacancies, maintains spatial proximity without aggregation, yet enable electron transfer pathways between Rh and Ni, preserving distinct active sites rather than forming bulk alloys. This allows the Ni to remain an active reforming site with Rh remaining as an electronic / hydrogen-activation site.

[0034] hi various embodiments, the nickel particles and the at least one noble metal particles (e.g., rhodium particles) may be homogenously dispersed on the surface of the support. Said differently, the nickel particles and the at least one noble metal particles are not aggregated on the surface of support. The nickel particles may comprise, for example, rhodium particles individually and evenly distributed across the surface of the support. The at least one noble metal particles (e.g., rhodium particles) may comprise noble metal particles (e.g., rhodium particles) individually and evenly distributed across the surface of the support. Advantageously, such features maximize accessible catalytic surface area, increasing hydrogen production rate, prevents metal aggregation thereby maintaining long-term catalytic stability and resistance to deactivation.

[0035] In various embodiments, each of the vacancies may arise from the absence of a transition metal atom and / or a chalcogen atom. These vacancies may act as high-energy anchoring sites for metal nanoparticles, enhancing dispersion and stability, as well as facilitate electron transfer pathways between support and metal particles, improvingcatalytic efficiency. Increased vacancy density may correlate with improved APR activity and resistance to poisoning.

[0036] In various embodiments, each of the vacancies may arise from the absence of a molybdenum atom and / or a sulfur atom. Sulfur and molybdenum vacancies may help to increase in-plane and edge active sites, enhancing water activation and reforming reactions, support stabilization of ultra-small (e.g., 2 nm or less) Ni and Rh particles for high hydrogen selectivity. This may help in consistent performance across monolayer, few-layer, and thick-layer MoS2variants.

[0037] In various embodiments, the nickel particles and the at least one noble metal particles (e.g., rhodium particles) may be structurally configured to facilitate transfer of electron from one noble metal particle (e.g., rhodium particle) to one nickel particle when the catalyst is operating in an alkaline environment. This may include the at least one layer of the transition metal dichalcogenide structured as a layer. In other words, the at least one transition metal dichalcogenide may be structured as a layer, and there may be various such layers each comprising a transition metal dichalcogenide. The various layers may be held together by van der Waals interactions or chemically bonded together. The at least one transition metal dichalcogenide may also exist as a layered sheet, and the catalyst may include various of such layered sheets dispersed therein. Each layered sheet may comprise one layer of the transition metal dichalcogenide or the various layers mentioned above.

[0038] In various embodiments, the catalyst may comprise an X-ray powder diffraction pattern having a single peak at 20 angles of 30.0° to 40.0°, 35.0° to 40.0°, 30.0° to 35.0°, etc.

[0039] In various embodiments, the catalyst may comprise an X-ray powder diffraction pattern which is absent of a peak at 20 angles of 10.0° to 30.0°, 20.0° to 30.0°, 10.0° to 20.0°, etc.

[0040] In various embodiments, the at least one noble metal particles (e.g., rhodium particles) may have an average size of 2 nm or less, and / or wherein the nickel particles may have an average size of less than 2 nm. Advantageously, these features may help maximize metal utilization efficiency, improve hydrogen formation rate and selectivity while minimizing undesired by-products, and contributes to higher catalytic activity compared to traditional metal catalysts at similar loadings.

[0041] In various embodiments and figures of the present disclosure, the catalyst may be denoted M@MoS2-xL, wherein M may represent the one or more transition metals, including the at least one noble metal (e.g., Rh-Ni for the presence of both rhodium and nickel particles), x may represent the layer structure, such as FL being a few layers (e.g., 15 to 20 layers), ML being a monolayer (e.g., 1 layer or 2 layers), and TL being a thick layer (3 to 14 layers), of the transition metal dichalcogenide (such as MoS2).

[0042] In various embodiments, the catalyst may be illustrated as shown in FIG. 4. The formula MoXndenotes the transition metal dichalcogenide support, wherein X denotes a chalcogen and n denotes an integer such as (but not limited to) 2.

[0043] The present disclosure provides for a method for forming the catalyst described in various embodiments of the first aspect. Embodiments and advantages described for the catalyst can be analogously valid for the method as subsequently described herein, and vice versa. As the various embodiments and advantages have already been described above and in examples demonstrated herein, they shall not be iterated for brevity.

[0044] In various embodiments, the method may comprise: providing a support comprising at least one layer of a transition metal dichalcogenide; and forming the transition metal particles dispersed on a surface of the support. The method provides controlled synthesis of vacancy-rich support with highly dispersed metal particles, and reproducible catalyst structures that offer consistent APR performance.

[0045] In various embodiments, providing the support may comprise: (i) forming an aqueous solution comprising a molybdenum-based precursor and a sulfur-based precursor, subjecting the aqueous solution to a hydrothermal treatment to render an intermediate support, and contacting the intermediate support with hydrogen gas to fonn the support; or (ii) forming an aqueous solution comprising a molybdenum-based precursor and a sulfur-based precursor, heating, then cooling, the aqueous solution to generate a precursor comprising molybdenum and sulfur, mixing the precursor with a reducing agent to form an aqueous mixture, subjecting the aqueous mixture to a hydrothermal treatment to render an intermediate support, and treating the intermediate support with plasma to form the support; or (iii) forming an aqueous solution comprising a surfactant, a precursor comprising molybdenum and sulfur, and a reducing agent, heating aqueous solution to render an intermediate support, calcining theintermediate support in the presence of nitrogen gas, and treating the intermediate support with plasma to form the support. Such features do not render bulk degradation and introduces controlled surface vacancies. The hydrogen reduction may help in formation of active metallic Ni and Rh phases.

[0046] In various embodiments, the method may involve treating the intermediate support with plasma to form the support. The plasma may comprise hydrogen-based plasma (e.g., hydrogen plasma).

[0047] In various embodiments, the molybdenum-based precursor may comprise ammonium heptamolybdate tetrahydrate ((NH4)6Mo7O24·4H2O), molybdenum nitride, molybdenum carbide, molybdenum boride, or molybdenum silicide, and the sulfurbased precursor may comprise thiourea, ammonium sulfide, carbon sulfide, or sodium sulfide; and / or the reducing agent may comprise hydrazine hydrate; and / or surfactant may comprise cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, or diammonium benzenesulfonate.

[0048] In various embodiments, forming the transition metal particles dispersed on the surface of the support may comprise: forming a mixture comprising ethylene glycol and water; mixing the mixture with the support and a precursor of the transition metal particles; subjecting the mixture (understandably aqueous) to a hydrothermal treatment to form an oxide of the transition metal particles; and contacting the oxide of the transition metal particles with hydrogen gas to form the transition metal particles. In various embodiments, the precursor of the transition metal particles may include any precursor that forms into a rhodium particle (an example of the at least one noble metal particle) and / or a nickel particle. In various embodiments, the method may involve contacting the oxide of the transition metal particles with hydrogen gas to form the transition metal particles. Such treatment of the oxide of the transition metal particles with hydrogen gas may reduce the oxide (e.g., nickel oxide and / or rhodium oxide) to its transition metal particles (e.g., nickel and / or rhodium).

[0049] In various embodiments, the hydrothermal treatment may be carried out in an autoclave and at a temperature of 180°C to 250°C, 190°C to 250°C, 200°C to 250°C, 210°C to 250°C, 220°C to 250°C, 230°C to 250°C, 240°C to 250°C, etc.

[0050] The present disclosure further provides for an alcohol aqueous phase reforming process. Embodiments and advantages described for the catalyst and method forforming the catalyst can be analogously valid for the process as subsequently described herein, and vice versa. As the various embodiments and advantages have already been described above and in examples demonstrated herein, they shall not be iterated for brevity.

[0051] In various embodiments, the process may comprise: providing the catalyst of various embodiments of the first aspect in a reactor, introducing an alcohol and an aqueous alkaline into the reactor to form a reaction mixture, and heating the reaction mixture to generate hydrogen gas and carbon dioxide.

[0052] In various embodiments, the alcohol aqueous phase reforming process may involve alcohol. The alcohol may include any substance with a hydroxyl group (e.g., -OH), for example, methanol, ethanol, isopropanol, butanol, glycerol, and ethylene glycol. In various embodiments, the alcohol may comprise methanol, ethanol, isopropanol, butanol, glycerol, or ethylene glycol. In various embodiments, the ethylene glycol is a non-limiting example of a reducing agent that aids in the formation of the transition metal particles.

[0053] In various embodiments, the aqueous alkaline may comprise potassium carbonate or sodium carbonate.

[0054] hi various embodiments, heating the reaction mixture may comprise heating the reactor to a temperature of 200°C to 250°C, 210°C to 250°C, 220°C to 250°C, 230°C to 250°C, 240°C to 250°C, etc.

[0055] In various embodiments, heating the reaction mixture may comprise heating the reactor under a pressure in a range of 10 bar to 30 bar, 20 bar to 30 bar, 10 bar to 20 bar, etc. For example, the alcohol aqueous phase reforming process may include heating the reaction mixture, which may comprise heating the reactor under a pressure in a range of, for example, 10 bar to 30 bar, 10 bar to 20 bar, 10 bar to 15 bar, 15 bar to 30 bar, or 15 bar to 20 bar.

[0056] hi various embodiments, the alcohol aqueous phase reforming process may further comprise: separating the hydrogen gas from the reaction mixture and the carbon dioxide; regenerating the aqueous alkaline from the reaction mixture after heating the reaction mixture; separating carbon dioxide from the aqueous alkaline that is regenerated; and recycling the aqueous alkaline into the reactor.

[0057] The word “substantially” does not exclude “completely” e.g. a composition which is “substantially free” from Y may be completely free from Y. Where necessary, the word “substantially” may be omitted from the definition of the present disclosure.

[0058] In the context of various embodiments, the articles “a”, “an” and “the” as used with regard to a feature or clement include a reference to one or more of the features or elements.

[0059] In the context of various embodiments, the tilde symbol the term “about”, and the term “approximately”, as applied to a numeric value encompasses the exact value and a reasonable variance. The variance may be ±20%, ±10%, ±5%, ±1%, ±0.5%, ±0.1%, etc.

[0060] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0061] Unless specified otherwise, the terms "comprising" and "comprise", and grammatical variants thereof, are intended to represent "open" or "inclusive" language such that they include recited elements but also permit inclusion of additional, unrecited elements.Examples

[0062] Examples of the present disclosure demonstrate for a catalyst suitable for alcohol aqueous phase reforming (APR). The catalyst may be a bi-functional catalyst. For example, the catalyst may be a nickel-rhodium (Ni-Rh) bi-functional catalyst for ethanol aqueous phase reforming (APR), advantageously configured for hydrogen production. The catalyst can be synthesized using a modified hydrothermal method, which significantly reduces the particle size of Ni and enhances its dispersion, leading to a 50% increase in catalytic activity compared to traditional catalysts. The interaction between Rh and Ni is advantageous, as electron transfer from Rh to Ni enhances the stability of Ni in strong alkaline environments, addressing traditional challenges faced by pure Ni catalysts. Rh is one non-limiting example of the at least one noble metal that confers such an advantage. Other non-limiting examples of the at least one noble metal may include gold, platinum, palladium, iridium, ruthenium, osmium, etc. In the various examples below, rhodium is used for the purpose of demonstration and not intended to limit the examples and the present disclosure.

[0063] Moreover, with the present catalyst, traditional KOH solution can be replaced with K2CO3 in alcohol aqueous phase reforming for CO2 adsorption. While KOH may traditionally offer higher catalytic performance, its regeneration tends to be undesirably complex and costly. In contrast, K2CO3 provides easier regeneration and recycling, contributing to a more economical and sustainable process. This advancement can also allow for the in-situ capture of CO2 during the reaction, which can enhance the overall efficiency of the APR process and eliminates the need for large volumes of electrolyte, leading to further cost savings.

[0064] The catalyst, method for forming such catalyst, and APR process involving such catalyst of the present disclosure, not only significantly boost catalytic efficiency, but also improve the long-term stability of the catalyst in harsh conditions, addressing the industry's growing need for sustainable and cost-effective hydrogen production. By configuring both the catalyst structure and the CO2 adsorption process, the present technology offers an advantageous green energy solution.

[0065] The catalyst, method for forming the catalyst, and the APR process involving the catalyst, are described in further details, by way of non-limiting examples, as set forth below.

[0066] Example 1: Experimental Method - Catalyst Synthesis

[0067] Synthesis of thick layer MoS2.

[0068] For the synthesis of thick layer MoS2(MoS2-TL), 1235.9 mg (NH4)6MO7O24-4H2O and 2283.6 mg of thiourea were dissolved in 35 mL deionized water to form a homogeneous solution. Then, the solution was sealed into a 100 mL Teflon-lined stainless- steel autoclave and maintained at 220°C for 18 hrs. Thereafter, the product was filtered and washed with pure water and absolute ethanol several times and then drying at 80°C. The dried product was then reduced in a tube furnace using 50 mL / min H2gas at 400°C for 3hrs. In summary, the steps can involve forming an aqueous solution comprising a molybdenum-based precursor and a sulfur-based precursor, subjecting the aqueous solution to a hydrothermal treatment to render an intermediate support, and contacting the intermediate support with hydrogen gas to form the support.

[0069] Synthesis of a few layers MoS2(MoS2-FL) supported metal catalysts.

[0070] Ammonium tetrathiomolybdate ((NH4)2MoS4, ATTM) was initially synthesized as a source of Mo and S for the subsequent preparation of few-layer and monolayerMOS2. In one example synthesis, 3700 mg of (NtUjeMo Oz LbO was dissolved in 30 niL of DI water. Then, 28 mL ammonium sulfide aqueous solution (20 wt%) was added to the solution, resulting in an immediate red-orange color change. The mixture was heated to 333 K with stirring for 1 hr. Subsequently, the solution was transferred to an ice bath without stirring and kept at this temperature for 3 hours. Following this, the solution was subjected to suction filtration, washed several times with isopropanol, and the resulting red crystals of ATTM were dried in a vacuum oven at 80°C overnight.

[0071] Further steps involved 0.7 g of ATTM dissolved in 30 mL of DT water, followed by the addition of 10 mL of hydrazine hydrate. This mixture was stirred for 1 hour. Then, the solution was placed in a hydrothermal autoclave reactor and subjected to hydrothermal synthesis at 200°C for 15 hours. After the hydrothermal synthesis, the solution was filtered and washed with IPA three times. The resulting product was dried in a vacuum oven at 60°C overnight. Finally, the dried product underwent plasma treatment to create surface sulfur vacancies.

[0072] In summary, the steps may involve forming an aqueous solution comprising a molybdenum-based precursor and a sulfur-based precursor, heating, then cooling, the aqueous solution to generate a precursor comprising molybdenum and sulfur, mixing the precursor with a reducing agent to form an aqueous mixture, subjecting the aqueous mixture to a hydrothermal treatment to render an intermediate support, and treating the intermediate support with plasma to form the support. These steps are part of the modified CTAB-assisted hydrothermal method of the present disclosure.

[0073] Synthesis of monolayer MoS2-supported metal catalysts.

[0074] 1 g of cetyltrimethylammonium bromide (CTAB) was dissolved in 320 mL of deionized water and stirred overnight in a 500 mL beaker at room temperature. After this, 0.7 g ATTM and 10 mL of hydrazine hydrate were added to the mixed solution, and the mixture was stirred for 1 hr. The reaction mixture was then transferred to a 1 L round bottom flask, equipped with a condenser, and set up in an oil bath. The reaction mixture underwent reflux for 5 hrs. After the reflux reaction, the product was obtained through filtration and washed with ethanol three times. Subsequently, the product was dried in a vacuum oven at 60°C overnight. The dried product was further treated in a tube furnace under a flow of 50 mL of nitrogen gas at 600°C for 4 hours. Finally, the calcined MoS2underwent plasma treatment to create surface sulfur vacancies. Insummary, the steps may involve forming an aqueous solution comprising a surfactant, a precursor comprising molybdenum and sulfur, and a reducing agent, heating aqueous solution to render an intermediate support, calcining the intermediate support in the presence of nitrogen gas, and treating the intermediate support with plasma to form the support. These steps arc part of the modified CTAB-assistcd reflux method.

[0075] Synthesis of MoS -supported metal catalyst.

[0076] A mixture of 30 mL of ethylene glycol and deionized (DI) water in a 1: 1 ratio was prepared, then a certain amount of previously prepared MoS2with different layers and an active metal precursor was added and stirred for half an hour. The resulting homogeneous mixture was then transferred to a hydrothermal autoclave reactor and subjected to hydrothermal synthesis at 200°C for 2 hours. The product was collected through filtration and washed with ethanol three times. Following this, the product was dried in a vacuum oven at 60°C overnight. The dried product was further treated in a tube furnace under a flow of 50 mL of hydrogen gas at 400°C for 2 hours, finally, the obtained product was labeled as M@MoS2-.xL, wherein x may represent the layer structure, such as FL being a few layers (e.g., 15 to 20 layers), ML being a monolayer (e.g., 1 layer or 2 layers), and TL being a thick layer (3 to 14 layers), of the transition metal dichalcogenide (such as MoS2).

[0077] Example 2: Catalysts Characterization and Results

[0078] The micro structures of MoS2prepared through various methods were meticulously examined using transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) (see FIG. 1 A to IF). FIG. 1 A clearly illustrates that MoS2prepared via a traditional hydrothermal method exhibits a well-layered structure, with at least 15-20 layers held together by van der Waals interactions. In contrast, MoS2prepared through the modified CTAB-assisted hydrothermal method of the present disclosure showed a significant reduction in the number of layers, with only 5-8 layers bonded together. Notably, the MoS2synthesized via the modified CTAB-assisted reflux method of the present disclosure revealed numerous single-layer MoS2sheets highly dispersed within the composites. As the number of layers decreases, more in-plane S surface and edge S surface become apparent. This characteristic is beneficial for anchoring surface-coating metals and providing additional active sites for the activation ofH2O.

[0079] The X-ray diffraction (XRD) patterns of MoS2prepared using different methods are presented in FIG. ID. The XRD patterns of annealed MoS2(FIG. ID) can be readily indexed as hexagonal 2H-MoS2(JCPDS 37-1492). MoS2prepared using the traditional method exhibited a very strong diffraction peak (002) at 20 = 14.2°, indicating a well-stacked layered structure, consistent with the TEM results. However, when the modified CTAB-assisted reflux method is employed, the (002) peak is nearly undetectable, signifying the absence of a well-stacked structure. Prior to supporting the surface-active metal sites, H2 plasma treatment was applied to create additional surface vacancies. A range of metals were subsequently deposited onto the treated material. In FIG. IE, it was observed that the MoS2-ML supported Rh catalyst, revealed highly dispersed Rh nanoparticles with a uniform particle size of less than 2 nm on the MoS2- This configuration highlights a substantial active metal surface area, which is of an advantage for the ethanol reforming reaction and H2 production.

[0080] The catalytic performance of MoSi-supported single metal and bi-metallic alloy catalysts was evaluated in ethanol aqueous phase reforming (APR) at 220°C and an initial pressure of 20 bar in a Parr reactor (see FIG. 2A to FIG. 2C). A 2M K2CO3 solution (X mL, wherein X may depend on the size of the vessel, in lab experiments of the present example, X can range from 5 mL to 30 mL) was used as the solvent in an inert Teflon vessel, with X mg of catalyst dissolved in the solution (wherein X may depend on the K2CO3 volume, in lab experiments of the present example, X can range from 5 mg to 100 mg), followed by ethanol addition to achieve a concentration of X wt% (wherein X can range from 0 to 30 wt%). After a 3-hour reaction, gas products were collected and analyzed using gas chromatography (GC) with thermal conductivity detector (TCD), and their quantities were calculated based on pressure changes. Comparative testing with commercial catalysts under identical conditions showed that the present MoS2-supportcd catalyst performed exceptionally well in the ethanol APR reaction, especially in H2 selectivity. By partially replacing Rh with the more affordable Ni using a modified hydrothermal method, the Rh-Ni@MoS2 catalyst achieved an impressive Hz formation rate of 679 pmol / min / g, a 60% improvement over the result from the traditional sample denoted Rh@MoS2-T (wherein T here denotes “traditional”), with a significant enhancement in H2 selectivity. When using KOH as the electrolyte, the H2 yield increased by over 30 times, demonstrating a remarkableenhancement in hydrogen production efficiency. This outstanding performance was attributed to the formation of a Rh-Ni alloy, where the synergy between Ni and Rh enhances both C-C bond cleavage and H2 formation rates, while maintaining the benefits of MoS2’s surface vacancies for effective metal dispersion. The electron transfer from Rh to Ni helps stabilize Ni under harsh conditions. Additionally, the use of K2CO3 solution allows for easy recovery, making it suitable for industrial production by significantly reducing the electrolyte consumption, thereby saving both cost and energy.

[0081] Example 3: Summary Discussion

[0082] The examples demonstrate an approach to developing a bi-functional catalyst, using Ni-Rh catalyst for the purpose of demonstration and not to limit the catalysts, for ethanol aqueous phase reforming (APR), significantly improving catalytic activity and stability. The strong interaction between Rh and Ni enhances electron transfer, which stabilizes Ni in harsh alkaline conditions where traditional Ni-based catalysts may be susceptible to degrade. Additionally, the catalyst can be obtained from improved hydrothermal synthesis methods described above to reduce the particle size of Ni and increase its dispersion, resulting in a 60% increase in catalytic activity compared to traditional catalysts and methods. The substitution of base solvent such as KOH with K2CO3 for CO2 capture represents another advantage, as it simplifies regeneration, reduces the need for large amounts of electrolyte, and enhances the sustainability of the process, all while maintaining acceptable catalytic performance. This combination of enhanced catalyst structure and process configuration makes the technology a unique solution for sustainable hydrogen production.

[0083] The Ni-Rh bi-functional catalyst, demonstrated as one of the non-limiting examples, offers enhanced activity and stability. K2CO3 simplifies regeneration and reduces costs. That said, in KOH system, catalytic performance may be improved by taking advantage of KOH's higher activity due to high pH environment. In parallel, efforts can be aimed to significantly increase the utilization efficiency of noble metals like Rh, ensuring that even small amounts of Rh are used advantageously. By configuring the synthesis process and improving noble metal dispersion, catalyst performance and cost-effectiveness may be further improved. This then helps in scaling up the technology for commercial applications.

[0084] The present catalyst may be a bi-functional Ni-Rh catalyst that leverages on the Rh-Ni interaction (an example of the noble metal and the transition metal interaction) to enhance catalytic activity and stability in strong alkaline environments, i.e., high activity and stability in harsh alkaline conditions.

[0085] The method (modified hydrothermal synthesis) of the present disclosure for forming such catalyst can help reduce Ni particle size and improve dispersion, increasing catalytic activity by 60% compared to traditional catalystprevious designs.

[0086] The catalyst structure, e.g, Ni-Rh Structure, is advantageous, for instance, Rh promotes electron transfer to Ni, stabilizing the Ni in harsh conditions, preventing degradation for long-term ethanol APR performance.

[0087] With the catalyst, use of K2CO3 as the CCh-absorbing solution simplifies CO2 absorption, regeneration, and recycling, reducing electrolyte amount and enhancing sustainability.

[0088] The catalyst has stable setive sites: Uniformly dispersed small metal particles across catalyst and support surfaces to maintain catalyst stability and prevent deactivation under challenging ethanol APR conditions and even strong alkaline conditions, and can be a sustainable approach for hydrogen production.

[0089] Example 4: Applications

[0090] The catalyst and method for forming the catalyst provide a technology which efficiently produces clean hydrogen through ethanol aqueous phase reforming (APR), making it ideal for use in a variety of sectors, including:

[0091] 1. Green hydrogen production for use in transportation, fuel cells, and power generation, addressing the growing demand for sustainable energy solutions.

[0092] 2. Industrial hydrogen supply in processes where clean hydrogen is required, such as chemical manufacturing and refining.

[0093] 3. Carbon capture and utilization (CCU) applications, where in-situ CO2 capture during APR can help reduce carbon emissions and contribute to carbon-neutral processes.

[0094] 4. Catalytic reactions involving Rh-Ni systems in challenging aqueous phase conditions, especially where the stability of metal catalysts in alkaline solutions may be advantageous.

[0095] 5. Broader catalytic applications where bi-functional catalysts and efficient metal dispersion may be necessary, including biomass conversion and biofuel production.

[0096] The method also holds potential for other catalytic reactions, particularly those requiring robust performance under harsh alkaline or aqueous conditions, enabling broader adoption of hydrogen-based energy systems.

[0097] The catalyst and method also constitute advantageous catalyst synthesis for improved cost-efficiency and enhanced performance, focusing on the Ni-Rh interaction and particle dispersion. The catalyst and method also offer long-term stability and durability of the catalyst under strong alkaline conditions, especially in ethanol aqueous phase reforming (APR) processes, and can be explored for new applications and markets, particularly in the areas of clean hydrogen production, industrial hydrogen supply, and carbon capture technologies, and for circumventing the recovery and regeneration of KOH as an absorbent solution, which could further enhance system performance and reduce operational costs due to the high pH environment. The catalyst can help to enhance energy efficiency, particularly in hydrogen production processes, to reduce energy consumption and improve the overall sustainability of the technology, and may serve as an incorporation of sustainability practices in all stages of development, ensuring that environmental impact assessments guide the configuration and scaling of the technology.

[0098] While the present disclosure has been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims. The scope of the present disclosure is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims arc therefore intended to be embraced.

Claims

1. CLAIMS1. A catalyst for alcohol aqueous phase reforming, the catalyst comprising: a support comprising at least one layer of a transition metal dichalcogenide; and transition metal particles dispersed on a surface of the support,wherein the transition metal particles comprise nickel particles and at least one noble metal particles, andwherein the nickel particles and the at least one noble metal particles are dispersed in proximity of vacancies residing in the at least one layer of the transition metal dichalcogenide.

2. The catalyst of claim 1, wherein the transition metal dichalcogcnidc comprises molybdenum disulfide, and / or wherein the at least one noble metal particles comprise rhodium, gold, platinum, palladium, iridium, ruthenium, and / or osmium.

3. The catalyst of claim 1 or 2, wherein the nickel particles and the at least one noble metal particles are homogenously dispersed on the surface of the support.

4. The catalyst of any one of claims 1 to 3, wherein each of the vacancies arises from the absence of a transition metal atom and / or a chalcogen atom.

5. The catalyst of any one of claims 1 to 4, wherein each of the vacancies arises from the absence of a molybdenum atom and / or a sulfur atom.

6. The catalyst of any one of claims 1 to 5, wherein the nickel particles and the at least one noble metal particles arc structurally configured to facilitate transfer of electron from one noble metal particle to one nickel particle when the catalyst is operating in an alkaline environment.

7. The catalyst of any one of claims 1 to 6, wherein the catalyst comprises an X ray powder diffraction pattern having a single peak at 20 angles of 30.0° to 40.0°.

8. The catalyst of any one of claims 1 to 6, wherein the catalyst comprises an X- ray powder diffraction pattern which is absent of a peak at 2θ angles of 10.0° to 30.0°.

9. The catalyst of any one of claims 1 to 8, wherein the at least one noble metal particles have an average size of 2 nm or less, and / or wherein the nickel particles have an average size of less than 2 nm.

10. A method for forming the catalyst of any one of claims 1 to 9, the method comprising:providing a support comprising at least one layer of a transition metal dichalcogenide; andforming the transition metal particles dispersed on a surface of the support.

11. The method of claim 10, wherein providing the support comprises:(i) forming an aqueous solution comprising a molybdenum-based precursor and a sulfur-based precursor,subjecting the aqueous solution to a hydrothermal treatment to render an intermediate support, andcontacting the intermediate support with hydrogen gas to form the support; or(ii) forming an aqueous solution comprising a molybdenum-based precursor and a sulfur-based precursor,heating, then cooling, the aqueous solution to generate a precursor comprising molybdenum and sulfur,mixing the precursor with a reducing agent to form an aqueous mixture, subjecting the aqueous mixture to a hydrothermal treatment to render an intermediate support, andtreating the intermediate support with plasma to form the support; or(iii) forming an aqueous solution comprising a surfactant, a precursor comprising molybdenum and sulfur, and a reducing agent,heating aqueous solution to render an intermediate support,calcining the intermediate support in the presence of nitrogen gas, and treating the intermediate support with plasma to form the support.

12. The method of claim 11, wherein:the molybdenum-based precursor comprises ammonium heptamolybdate tetrahydrate (((NH4)6Mo7O24·4H2O), molybdenum nitride, molybdenum carbide, molybdenum boride, or molybdenum silicide, and the sulfur-based precursor comprises thiourea, ammonium sulfide, carbon sulfide, or sodium sulfide; and / orthe reducing agent comprises hydrazine hydrate; and / orsurfactant comprises cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, or diammonium benzenesulfonate.

13. The method of any one of claims 10 to 12, wherein forming the transition metal particles dispersed on the surface of the support comprises:forming a mixture comprising ethylene glycol and water;mixing the mixture with the support and a precursor of the transition metal particles;subjecting the mixture to a hydrothermal treatment to form an oxide of the transition metal particles; andcontacting the oxide of the transition metal particles with hydrogen gas to form the transition metal particles.

14. The method of claim 13, wherein the hydrothermal treatment is carried out in an autoclave and at a temperature of 180°C to 250°C.

15. An alcohol aqueous phase reforming process, the process comprising:providing the catalyst of any one of claims 1 to 9 in a reactor; introducing an alcohol and an aqueous alkaline into the reactor to form a reaction mixture; andheating the reaction mixture to generate hydrogen gas and carbon dioxide.

16. The alcohol aqueous phase reforming process of claim 15, wherein the alcohol comprises methanol, ethanol, isopropanol, butanol, glycerol, or ethylene glycol.

17. The alcohol aqueous phase reforming process of claim 15 or 16, wherein the aqueous alkaline comprises potassium carbonate or sodium carbonate.

18. The alcohol aqueous phase reforming process of any one of claims 15 to 17, wherein heating the reaction mixture comprises heating the reactor to a temperature of 200°C to 250°C.

19. The alcohol aqueous phase reforming process of any one of claims 15 to 18, wherein heating the reaction mixture comprises heating the reactor under a pressure in a range of 10 bar to 30 bar.

20. The alcohol aqueous phase reforming process of any one of claims 15 to 19, further comprising:separating the hydrogen gas from the reaction mixture and the carbon dioxide; regenerating the aqueous alkaline from the reaction mixture after heating the reaction mixture;separating carbon dioxide from the aqueous alkaline that is regenerated; and recycling the aqueous alkaline into the reactor.

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