Sorbent for capturing gas, such as carbon dioxide, from gas stream

Abstract

Compositions, methods of production, methods of use, and systems for humidity swing adsorbents can be applied to capture carbon dioxide or other target chemicals from air or other gas streams. The compositions, methods, and systems may use a humidity swing sorbent comprising a sorbent support layer of an oxide nanoparticle material or nanoporous material and a capture layer comprising a set of neutral ion pairs having at least one cation and at least one anion, wherein the set of neutral ion pairs is spatially distributed over the scaffold of oxide material such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion wherein the hydrated shell around the anions is a carbon dioxide adsorption site.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 468,850, filed May 25, 2023, which is incorporated herein by reference in its entirety. Background Technology

[0003] Climate change necessitates engineering solutions to address the excess CO2 already added to the atmosphere. The urgency of capturing CO2 from ambient air is well-established. However, acceptance of technologies for direct air capture (DAC) CO remains limited due to the cost and technical challenges of addressing this issue. CO2 removal offers numerous benefits, including but not limited to mitigating the impacts of global climate change, improving public health, maintaining animal and plant diversity, and other environmental benefits. Converting CO2 into synthetic fuels is also one of the most important goals on the UN Sustainable Development Agenda.

[0004] There are many challenges in the field of DACs. One challenge is the low concentration of CO2 in the air, making it difficult to capture. Another challenge is the limitations of the conventional materials used in existing DAC technologies.

[0005] Existing DAC technologies generally fall into five categories: physical adsorption, adsorption via strong bases, adsorption via amine-modified materials, adsorption via amino acid aqueous solutions followed by precipitation into guanidine compounds, and electrochemical adsorption. However, the traditional materials used as adsorbents in these DAC technologies are unstable, difficult to scale up, have low selectivity (sometimes absorbing large amounts of water from the air), and / or have high energy costs (e.g., for material regeneration).

[0006] Many physical adsorbents also capture H2O from the air when capturing CO2, and air humidity levels can have a detrimental effect on CO2 adsorption capacity. Furthermore, the most commonly used amine-modified materials exhibit significant degradation problems during heating processes (for regeneration after CO2 capture). DAC adsorbents must be able to withstand thousands of cycles without excessive performance loss in order to reduce the cost of CO2 capture to below $100 per tonne, which is essential for providing an economically viable process.

[0007] An exemplary capture method disclosed in U.S. Patent No. 9,283,510 uses a polymer-based amine anion exchange resin to directly capture CO2 from the air. However, such resins have been found to have undesirable CO2 adsorption / desorption kinetics. Consequently, the adsorption / desorption cycle time is long, lasting ten hours or more (as shown in Figure 1). Accordingly, the material limitations of such resins severely restrict the practical feasibility of such solutions.

[0008] Therefore, in the field of carbon capture technology, it is desirable to develop compositions, methods, and systems for humidity swing sorbents that can be used for direct air capture of carbon dioxide. Summary of the Invention

[0009] This disclosure generally relates to the field of gas adsorption technology, such as carbon capture technology, and more specifically to novel and useful compositions, methods, and systems of humidity-controlled oscillating adsorbents for direct air capture of carbon dioxide. To address problems in the fields of carbon capture and / or capture of other target gases (such as toxic gases), some aspects of this disclosure relate to humidity-controlled oscillating adsorbents for direct air capture of CO2 and CO2 capture from flue gas, as well as the controlled release of CO2 and the reuse of humidity-controlled oscillating adsorbents. Humidity-controlled oscillating adsorbents may have similar capabilities for other target gases.

[0010] Some aspects of this disclosure relate to a series of ion-functionalized adsorbent materials that facilitate responses to humidity oscillations for the capture and release of target gases, particularly CO2. Such aspects may involve ion-functionalized materials that utilize a support layer as a scaffold for constructing a capture layer in which different ion pairs (or ion assemblies) are arranged at intervals, and a hydrated shell can be formed around the ion pairs to serve as a mechanism for capturing CO2 based on humidity oscillations. The support layer may also be referred to as a substrate material.

[0011] This disclosure is configured to use an adsorbent with ion-functionalized material to chemically capture CO2 from air under dry conditions and release CO2 upon increasing moisture content (humidity swing). Returning the adsorbent to dry conditions allows for its regeneration, wherein the regenerated adsorbent can capture CO2 from ambient air after drying. It should be understood that, as used herein, "dry" and "wet" conditions are relative. For example, a material can be considered "dry" as long as it contains less water than a material considered "wet," and a "wet" material can be unsaturated with water. Compared to state-of-the-art resin materials, the adsorbent of this disclosure can exhibit significantly enhanced CO2 capture as well as regeneration kinetics and / or other benefits. Some aspects may utilize nanoporous or mesoporous support layer materials, such as mesoporous oxides. Some aspects may utilize oxide nanoparticles as the support layer. Advantageously, it has been found that the adsorbent material of this disclosure can be simply dried by passing ambient air through it. When the adsorbent material returns to its "dry" state, the adsorbent begins to adsorb CO2 from the air. Therefore, special "drying" treatment may not be necessary. Conversely, the adsorbent disclosed herein can be simply (re)exposed to ambient air containing, for example, CO2 for removal upon wetting to release the previously captured CO2.

[0012] According to a first aspect of the disclosed subject matter, an adsorbent composition for adsorbing a target gas from a gas stream is provided. The adsorbent composition may include a covalently linked solid oxide substrate material functionalized with ion-linking groups. The substrate may alternatively be referred to as an adsorbent support layer. The adsorbent composition may optionally be described as a humidity-swirling adsorbent composition. Optionally, each ion-linking group comprises a polyvalent anion and a polyatomic cation. Optionally, the polyatomic cation is selected from ammonium, phosphonium, arsenic, antimony, bismuth, and sulfonium. Optionally, the polyatomic cation is covalently bonded to oxygen atoms on the surface of the substrate material. According to a second aspect of the disclosed subject matter, an adsorbent precursor for an adsorbent composition for adsorbing a target gas from a gas stream is provided. Optionally, the adsorbent precursor is a precursor of the adsorbent composition of the first aspect of the disclosed subject matter. Optionally, the adsorbent precursor comprises a covalently linked solid oxide substrate material functionalized with an ion-linking group precursor. Optionally, the linking group precursor comprises a monovalent anion and a polyatomic cation, optionally covalently bonded to oxygen atoms on the surface of the substrate material. Optionally, the target gas is carbon dioxide.

[0013] Optionally, the polyatomic cation has the formula R(R'). x A + Optionally, R is a hydrocarbon-containing group covalently bonded to an oxygen atom on the surface of the substrate material, or R is a covalent bond to an oxygen atom on the surface of the substrate material. R is optionally substituted C1 to C8 hydrocarbon group. Optionally, each R' is independently a hydrocarbon-containing group or H. Optionally, R' is a C1 to C6 alkyl group (such as methyl, ethyl, propyl, or butyl), or R' is an aryl group (such as phenyl). Optionally, x is 3, and A is N, P, As, Sb, or Bi. Optionally, x is 2, and A is S. Optionally, the polyatomic cation is ammonium, phosphonium, or sulfonium. Optionally, the polyatomic cation is an ammonium cation, such as a quaternary ammonium cation, for example, a cation containing trimethylammonium.

[0014] Optionally, the polyatomic cations are spaced apart on the surface (e.g., in the pores) of the covalent network solid oxide material, wherein the average spacing is no more than about 50 Å, such as no more than about 20 Å, for example no more than about 10 Å. Alternatively or additionally, the polyatomic cations are spaced apart at a distance of about 4 Å to about 50 Å, such as about 6 Å to 20 Å, for example about 8 Å to 10 Å.

[0015] It should be understood that polyvalent anions possess multiple negative charges, such as 2-, 3-, or 4-. Optionally, polyvalent anions contain or consist of oxygen and elements from or derived from Group 15 or Group 16 of the periodic table. Optionally, polyvalent anions are selected from: BO3 3- CO3 2 C2O42- SiO4 4- PO3 3- PO4 3- SO3 2- and SO4 2- Optionally, the polyvalent anion contains or is composed of hydrogen, oxygen, and elements from or derived from Group 15 or Group 16 of the periodic table, for example, the polyvalent anion is selected from: HBO3 2- HCO3 - HC2O4 - HSiO4 3- HPO3 2- HPO4 2- HSO3 - and HSO4 - Optionally, the adsorbent composition further comprises the formula (TG)OH - The anions of TG, where TG is the target gas, and (TG)OH - It exists in a molar ratio of approximately 1:1 with polyvalent anions. Optionally, the target gas is CO2, and (TG)OH - HCO 3- .

[0016] Optionally, the adsorbent composition comprises a polyvalent anion in an amount of about 0.2 mmol to about 3 mmol per gram of covalent network solid oxide material, such as about 0.3 mmol to about 2.5 mmol, for example about 0.5 mmol to about 2 mmol.

[0017] Optionally, the substrate material is functionalized by reacting each oxygen atom on the surface of the substrate material with a carbon atom of a nucleophilically vulnerable linker precursor reactant to form a CO covalent bond. Optionally, the linker precursor reactant comprises a cation selected from N-[3-(trimethoxysilyl)propyl]-N,N,N-trimethylammonium, N-(trimethoxysilylpropyl)-N,N,N-trimethylphosphonium, and glycidyltrimethylammonium. Optionally, the substrate material is functionalized by reacting each oxygen atom on the surface of the substrate material with an epoxy group of the linker precursor reactant to form a CO covalent bond. For example, hydroxyl groups on the substrate surface may form an OC covalent bond through a ring-opening reaction with an epoxy group. Optionally, the linker precursor reactant comprises a glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each oxygen atom on the surface of the substrate material with an epoxy group of the glycidyltrimethylammonium cation to form a CO covalent bond.

[0018] Optionally, the covalent network solid oxide substrate material includes one or more of silicon dioxide, aluminum oxide, cerium dioxide, zirconium oxide, iron oxide, and aluminosilicate.

[0019] Optionally, the adsorbent composition comprises water. Optionally, the water is present in a water:polyvalent anion molar ratio of 1:10 to 40:1, such as 1:1 to 1:20. Such water content in the adsorbent composition is understood as the "dry" state of the adsorbent composition, wherein the water is present at a sufficiently low concentration to allow water molecules to form a stable hydrated shell around the polyvalent anion (described in more detail below). When the adsorbent is in a dry state, the adsorbent can be configured for the adsorption of a target gas (e.g., CO2 capture). Alternatively, the water is present in a water:polyvalent anion molar ratio greater than 40:1, such as at least 50:1. Such water content in the adsorbent composition is understood as the "wet" state of the adsorbent composition, wherein the water is present at a concentration in which such hydrated shells are disrupted. When the adsorbent is in a wet state, the adsorbent can be configured for the desorption of a target gas (e.g., CO2 release).

[0020] According to a third aspect of the disclosed subject matter, a composition of an adsorbent for adsorbing carbon dioxide is provided. The composition may include an adsorbent support layer; and a trapping layer comprising an ion-modified material having at least one carbon dioxide adsorption site thereon. It should be understood that the ion-modified material may be used, for example, for discontinuous layers, such as by depositing the ion-modified material onto the surface of the adsorbent support layer. The ion-modified material may also be referred to as an "ion pair." The term "ion pair" may refer to a neutral ionic material comprising one or more cations and one or more anions that are ion-bonded and charge-balanced. Optionally, at least one anion of the ion pair is a polyvalent anion. Optionally, the ion-modified material comprises polyatomic cations and / or polyvalent anions as described above. It should be understood that one aspect or embodiment of the disclosed subject matter may be incorporated into any feature disclosed with respect to another aspect or embodiment of the disclosed subject matter. For example, the adsorbents and / or adsorbent precursors of the first and second aspects may respectively incorporate any feature disclosed with respect to the adsorbent of the third aspect, and vice versa.

[0021] In some variations, the adsorbent support layer can be made of oxide materials. It should be understood that oxide materials can be compounds containing oxygen and at least one other element and being solid at ambient temperature and pressure. More specifically, oxide materials can be covalent network solids. Covalent network solids, also known as atomically crystalline solids or giant covalent structures, are compounds in which atoms are covalently bonded in a continuous network extending throughout the material, for example, producing crystalline or amorphous macromolecular solids.

[0022] In some variants, the adsorbent support layer is made of a nanoporous material. It should be understood that a nanoporous material is a material having pores with diameters ranging from about 1 nm to about 1000 nm. In some variants, the adsorbent support layer is made of a mesoporous material. It should be understood that a mesoporous material is a material having pores with diameters ranging from about 2 nm to about 50 nm. The pore size can be measured by any suitable method, for example, by N2 adsorption at 77 K.

[0023] In some variants, the adsorbent carrier layer can be made of oxide nanoparticle materials or nanoporous materials.

[0024] In some embodiments, the ion-modified material is a combination of positively charged ions (cations) and negatively charged ions (anions).

[0025] In some variations, the ion-modified material comprises a set of ion pairs, which may be ion assemblies or complexes of ion (cations and anions) combinations, and may be electrically neutral. Accordingly, in another aspect of the disclosed subject matter, a composition of an adsorbent for adsorbing carbon dioxide comprises: an adsorbent support layer made of an oxide material; and a trapping layer comprising a set of neutral ion pairs having at least one cation and at least one anion, wherein the set of neutral ion pairs is spatially distributed on the oxide material support such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is a carbon dioxide adsorption site.

[0026] In some embodiments, the oxide material is a nanoporous oxide material.

[0027] In some embodiments, the oxide material is a mesoporous oxide material.

[0028] In some embodiments, the ion-modified material is contained within the pores of the nanoporous oxide material. Optionally, the nanoporous oxide material contains pores containing the ion-modified material.

[0029] In some embodiments, the oxide material is a nanoporous oxide material, and a set of neutral ion pairs spatially distributed on the scaffold of the oxide material are contained in the pores of the oxide nanoporous material.

[0030] Accordingly, in some embodiments of the disclosed subject matter, the composition of the adsorbent for adsorbing carbon dioxide includes: an adsorbent carrier layer made of an oxide material; and a trapping layer comprising a set of neutral ion pairs having at least one cation and at least one anion, wherein the set of neutral ion pairs is contained in the pores of the oxide nanoporous material such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is a carbon dioxide adsorption site.

[0031] In some variations, the support layer may comprise a nanoporous material, which may be an oxide nanoporous material or a non-oxide nanoporous material. Accordingly, in some embodiments of the disclosed subject matter, the composition of the adsorbent for adsorbing carbon dioxide may comprise an adsorbent support layer made of a nanoporous material; and a trapping layer comprising an ion-modified material having at least one carbon dioxide adsorption site thereon, and the ion-modified material being contained within the pores of the nanoporous material. In some variations of the embodiments, the composition may comprise: an adsorbent support layer made of a nanoporous material; and a trapping layer comprising a set of neutral ion pairs having at least one cation and at least one anion, wherein the set of neutral ion pairs is contained within the pores of the oxide nanoporous material such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is a carbon dioxide adsorption site.

[0032] In some embodiments, the nanoporous material is an oxide nanoporous material.

[0033] In some embodiments, the nanoporous material is a non-oxide nanoporous material. In some embodiments, the nanoporous material is a material comprising or selected from the group consisting of: activated carbon, quartz, zeolite, carbon nanotubes, organometallic frameworks, and covalent organic frameworks.

[0034] Optionally, the pores of the nanoporous oxide material contain anions with an average of no more than 20 neutral ion pairs per pore. In some embodiments, when fewer than 20 anions are present in the pores, the neutral ion pairs contained in the pores of the oxide nanoporous material have anionic amorphous spacing to form a hydrated shell. It should be understood that, as used herein, the amorphous spacing is an anionic spacing greater than the spacing present in the crystalline form of the ionic material. For example, if the ionic material is sodium carbonate, the amorphous spacing is an anionic spacing greater than the spacing between carbonate anions in crystalline sodium carbonate. Optionally, the amorphous spacing is at least twice, such as at least three times, the anionic spacing in the corresponding crystalline material.

[0035] In some embodiments, the oxide material is an oxide nanoparticle material. It should be understood that the nanoparticle material comprises or is composed of particulate material, which consists of particles having a maximum size (e.g., length, width, height, and / or diameter) of 1 nm to 1000 nm.

[0036] In some embodiments, the ion-modified material is bonded to the surface of and / or around the surface of the nanoparticles in the oxide nanoparticle material.

[0037] In some embodiments, the oxide material is an oxide nanoparticle material, and a set of neutral ion pairs spatially distributed on the scaffold of the oxide material are spaced apart by each of at least one cation spatially grafted onto the oxide nanoparticle material.

[0038] Accordingly, in some embodiments of the disclosed subject matter, a composition of an adsorbent for adsorbing carbon dioxide includes: an adsorbent support layer made of an oxide material; and a trapping layer comprising a set of neutral ion pairs having at least one cation and at least one anion, wherein each cation of the at least one cation of the set of neutral ion pairs is spatially grafted onto the oxide nanoparticles of the oxide nanoparticle material, such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is a carbon dioxide adsorption site. As used herein, ion pairs are grafted onto a material (such as a support material) when a covalent bond is formed between the cation of the ion pair or each cation and the material.

[0039] In some embodiments, there are multiple neutral ion pairs grafted onto the nanoparticles of the oxide nanoparticle material.

[0040] In some embodiments, neutral ion pairs are spatially grafted onto or around oxide nanoparticles, such that the anions of the neutral ion pairs have a non-crystalline spacing.

[0041] In some embodiments, the hydration shell around each anion of a set of neutral ion pairs is conditioned to a humidity state. Alternatively or additionally, the number of water molecules contained in the hydration shell may depend at least in part on the relative humidity of the surrounding environment. For example, the number of water molecules contained in the hydration shell may be higher under higher humidity conditions than under lower humidity conditions. It should be understood that the number of water molecules in the hydration shell may be referred to as the water quantity or the number of water molecules. It should further be understood that the water molecules contained in the hydration shell are water molecules held in place by interaction with the anions of the ion-modified material, such as water molecules forming hydrogen bonds with the anions. It should be understood that such hydrogen-bonded water molecules may, for example, form an ordered structure around and / or adjacent to the anions. It has been found that allowing the adsorbent material of this disclosure to balance its moisture content in an environment with a relative humidity not exceeding 45% will bring the adsorbent into a “dry” state (i.e., capable of adsorbing a sufficient amount of CO2 to provide a commercially viable carbon capture system). It has also been found that when the adsorbent reaches equilibrium at a relative humidity >99%, substantially all of the captured CO2 will be released.

[0042] In some embodiments, when under hydrated shell conditions based on the number of water molecules, the presence of carbon dioxide drives a first reaction between carbon dioxide, the hydrated shell, and anions to form at least bicarbonate ions within the hydrated shell.

[0043] In some embodiments, the hydration shell condition based on the number of water molecules is when the number of water molecules is less than at least 50. In some embodiments, the hydration shell condition based on the number of water molecules is when the number of water molecules is less than at least 30. In some embodiments, the hydration shell condition based on the number of water molecules is when the number of water molecules is less than at least 20. In some embodiments, the hydration shell condition based on the number of water molecules is when the number of water molecules is less than at least 10. It should be understood that the number of water molecules per anion suitable for forming a stable hydration shell can depend on the anion. For example, it has been found that carbonate ions can form hydration shells with fewer water molecules than phosphate anions. For example, the typical number of water molecules can be determined by quantum chemistry based on ordered structures.

[0044] In some embodiments, when the hydrated shell decomposes under conditions based on the number of water molecules, the hydrated shell decomposes through a second reaction that releases CO2 from bicarbonate ions into water (e.g., aqueous phase water).

[0045] In some embodiments, the condition for the decomposition of the hydrated shell based on the number of water molecules is when the number of water molecules is greater than 50. In some embodiments, the condition for the decomposition of the hydrated shell based on the number of water molecules is when the number of water molecules is greater than 30. In some embodiments, the condition for the decomposition of the hydrated shell based on the number of water molecules is when the number of water molecules is greater than 20. In some embodiments, the condition for the decomposition of the hydrated shell based on the number of water molecules is when the number of water molecules is greater than 10.

[0046] The adsorption and desorption of CO2 on an adsorbent can be described by the following equilibrium, for example, when the anion contains boron, carbon, silicon, phosphorus, or sulfur:

[0047]

[0048] Where A is B, C, Si, P, or S, and x and y are independently at least 2. Optionally, when A is B, x is 3, y is 3, and z is 1. Optionally, when A is C: x is 3, y is 2, and z is 1; or, x is 4, y is 2, and z is 2. Optionally, when A is Si, x is 4, y is 4, and z is 1. Optionally, when A is P: x is 3, y is 3, and z is 1; or, x is 4, y is 3, and z is 1. Optionally, when A is S: x is 3, y is 2, and z is 1; or, x is 4, y is 2, and z is 1. In the equilibrium equation above, the forward reaction of equilibrium (where CO2 is consumed) can be called the first reaction, and the reverse reaction (where CO2 is produced) can be called the second reaction. It should be understood that the equilibrium position controls the CO2 capture state of the material, and adding or removing water from the system can shift the equilibrium position toward free CO2 or captured CO2. More specifically, when the water concentration is low, the equilibrium is on the right, which favors CO2 capture, while an increase in water concentration shifts the equilibrium to the left, which favors CO2 release.

[0049] In some embodiments, at least one anion is borate ion (BO3). 3- The first reaction is characterized by:

[0050] ,

[0051] And the second reaction is characterized by:

[0052] .

[0053] In some embodiments, at least one anion is carbonate ion (CO3-). 2- The first reaction is characterized by:

[0054] ,

[0055] And the second reaction is characterized by:

[0056] .

[0057] In some embodiments, at least one anion is oxalate ion (C2O4). 2- The first reaction is characterized by:

[0058] ,

[0059] And the second reaction is characterized by:

[0060] .

[0061] In some embodiments, at least one anion is a silicate ion (SiO4). 4- The first reaction is characterized by:

[0062] ,

[0063] And the second reaction is characterized by:

[0064] .

[0065] In some embodiments, at least one anion is sulfite ion (SO32-). 2- The first reaction is characterized by:

[0066] ,

[0067] And the second reaction is characterized by:

[0068] .

[0069] In some embodiments, at least one anion is sulfate ion (SO4). 2- The first reaction is characterized by:

[0070] ,

[0071] And the second reaction is characterized by:

[0072] .

[0073] In some embodiments, at least one anion is a phosphate ion (PO3). 2- The first reaction is characterized by:

[0074] ,

[0075] And the second reaction is characterized by:

[0076] .

[0077] In some embodiments, at least one anion is a phosphate ion (PO4). 3- The first reaction is characterized by:

[0078] ,

[0079] And the second reaction is characterized by:

[0080] .

[0081] In some embodiments, the hydration shell has one to three layers. It should be understood that the layers of the hydration shell are layers of water molecules spaced approximately the same distance from the anions, with lower layers (inner layers) closer to the anions than higher layers (outer layers). Optionally, the hydration shell comprises a first layer and optionally one or more additional layers. It should be understood that the first layer is a layer of water molecules that interact directly with the solute (anion in this example). The distance between the solute and the first hydration shell is typically about 2.0 Å to 3.5 Å, depending on the size and charge of the ions. The second layer is a layer containing or composed of water molecules that interact indirectly with the solute through hydrogen bonds with the water molecules in the first layer. The distance from the solute to the second layer is typically about 4.0 Å to 6.0 Å. Subsequent layers tend to have less defined distances from the solute, while the hydrogen atoms of the water molecules are bonded to adjacent inner layers, and the layers extend outward in increments of about 2 Å to 3 Å per layer.

[0082] In some embodiments of the composition, in a dry state, the adsorbent adsorbs CO2 by converting CO2 into carbonate anions in the presence of a gas stream, and in a humid state, the adsorbent releases CO2. Subsequently, upon drying, the trapping layer reverts to a set of neutral ion pairs with a hydrated shell upon returning to a dry state. Without being bound by theory, it is believed that the proximity of water molecules in the hydrated shell to the surrounding anions promotes the dissociation of water into H+. + and OH - This facilitates the reaction with CO2 to form carbonate anions (HCO3-). - ) and the protonated form of anions in the hydrated shell (in the above terminology, a protonated anion has the formula HA) z O x (y-1)-The carbonate anion and protonated anion together act as counterions to the cations in the ion-modified material, thereby capturing CO2 until the equilibrium reaction reverses. When the adsorbent material is ready for carbon capture in its "dry" state, water molecules remain in the material to form a hydrated shell around the ion pairs, resulting in a high water concentration in the local environment immediately surrounding the ion pairs on the adsorbent surface. Water molecules are held in place by hydrogen bonds between themselves and the anions of the ion pairs. When exposed to CO2, the increased CO2 concentration may drive the equilibrium reaction forward, favoring the reaction of CO2 with water to form carbonate anions. It is further believed that increasing the water concentration on the adsorbent surface (i.e., by wetting the adsorbent material) destabilizes the hydrated shell because the presence of additional water molecules disrupts the hydrogen bonds between the water molecules in the hydrated shell and the anions of the ion pairs. Therefore, the local water concentration (i.e., the concentration of water molecules in the immediate vicinity of the ion pairs) may decrease, driving the equilibrium backward and thus favoring the reformation of CO2.

[0083] To avoid being bound by theory, it is believed that, for example, when the anion in the trapping layer is carbonate, the carbonate anion and water molecules in the hydrated shell can exist in the following equilibrium:

[0084]

[0085] The equilibrium releases hydroxide ions, which react with CO2 to form bicarbonate ions in the reaction equilibrium disclosed above. It should be understood that the amount of water in the equilibrium system controls the position of the equilibrium. It has been found that when n is 10, the free energy of the forward reaction (i.e., the formation of hydroxide ions) reverses from positive to negative; a value of n above 10 produces a positive free energy (thus favoring the formation of carbonate ions), while a value of n below 10 produces a negative free energy (thus favoring the formation of both bicarbonate and hydroxide ions). In dried adsorbent materials, n is the amount of water, or the number of water molecules per anion. Therefore, by drying such adsorbent materials to reduce n to 10, hydroxide ions can be used to react with CO2 to form carbonate ions.

[0086] In some embodiments, the nanoporous oxide material comprises or is selected from the group consisting of: aluminum oxide (Al2O3) (also known as alumina), silicon oxide (SiO2) (also known as silicon dioxide), cerium oxide (CeO2) (also known as cerium dioxide), zirconium oxide (ZrO2) (also known as zirconium oxide), and iron oxide (FeO2). x Such as Fe2O3 and / or FeO), aluminosilicates, mesoporous oxide ceramics, and mixtures thereof.

[0087] In some embodiments, the oxide material comprises or is a combination of materials selected from the group consisting of: aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), and iron oxide (FeO₂). x ) as well as aluminosilicate and mesoporous oxide ceramics.

[0088] In some embodiments, at least one cation (e.g., the positively charged ion of an ion pair) comprises or is selected from the group of positively charged ions (i.e., the group of cations) consisting of: Na + K + and polyatomic cations (such as glycidyltrimethylammonium (GTA)) + ), and at least one of the anions (e.g., a polyvalent anion) (e.g., the negatively charged ion of an ion pair) comprises or is selected from the group of negatively charged ions (i.e., the group of anions) consisting of: carbonate (CO3) 2- ), oxalate (C2O4) 2- ), phosphate (PO4) 3- ), phosphate (PO3) 2- ), sulfite (SO3) 2- ), sulfate (SO 4- ), borate (BO3) 3- ) and silicate (SiO4) 4- ).

[0089] In some embodiments, the ion pair comprises two polyatomic cations (such as glycidyltrimethylammonium (GTA)). + (cations) and anions (e.g., polyvalent anions), such as anions comprising or selected from the following negatively charged ion group (i.e., the anion group): carbonate (CO3) 2- ), oxalate (C2O4) 2- ), phosphate (PO4) 3- ), phosphate (PO3) 2- ), sulfate (SO 4- ), sulfite (SO3) 2- ), borate (BO3) 3- ) and silicate (SiO4) 4- ).

[0090] In some embodiments, a set of neutral ion pairs is a combination of a neutral ion pair and different anions selected from the group of negatively charged ions.

[0091] In some embodiments, at least one cation (e.g., the positively charged ion of an ion pair) comprises or is selected from the group of positively charged ions (i.e., the group of cations) consisting of: Na + K +and polyatomic cations (such as glycidyltrimethylammonium (GTA)) + (), and at least one of the anions (e.g., a polyvalent anion) (e.g., the negatively charged ion of an ion pair) comprises or is selected from the group of anions consisting of: carbonate, oxalate, silicate, phosphate, phosphite, sulfate, sulfite and borate.

[0092] It should be understood that a set of neutral ion pairs may comprise a mixture of cations and / or anions, for example, where each individual ion pair is the same or different.

[0093] According to a fourth aspect of the disclosed subject matter, a method is provided for preparing an adsorbent composition for adsorbing a target gas from a gas stream. Optionally, the method comprises forming the adsorbent precursor by contacting a covalent network solid oxide substrate material with a linker precursor reactant, contacting the adsorbent precursor with an ionic compound comprising a metal from Group 1 or Group 2 of the periodic table and a polyvalent anion, and removing a salt comprising a metal from Group 1 or Group 2 of the periodic table and a monovalent anion. Optionally, the linker precursor reactant comprises anions and polyatomic cations. Optionally, the polyatomic cation is selected from ammonium, phosphonium, arsenic, antimony, bismuth, and sulfonium. Optionally, the contacting of the covalent network solid oxide substrate material with the linker precursor reactant is performed under conditions that are effective for the covalent bonds between oxygen atoms and polyatomic cations on the surface forming the substrate material. Optionally, the contacting of the adsorbent precursor with the ionic compound is performed under conditions that are effective for inducing ion exchange, thereby exchanging the polyvalent anion for a monovalent anion. Optionally, the method includes forming a suspension of a covalent network solid oxide material in an aqueous solution (such as water), optionally adding a linker precursor reactant to the suspension to form an intermediate mixture, and optionally adding an ionic compound to the mixture of the suspension and the linker precursor reactant to form a product mixture. Optionally, the salt removal step includes centrifuging the product mixture, optionally thereby separating a byproduct solution containing water and salt from the adsorbent composition. According to a fifth aspect of the disclosed subject matter, a method for preparing an adsorbent precursor for an adsorbent composition for adsorbing a target gas from a gas stream is disclosed. Optionally, the method of the fifth aspect forms a precursor adsorbent formed by the method of the fourth aspect. Optionally, the method includes contacting a covalent network solid oxide substrate material with a linker precursor reactant. Optionally, the linker precursor reactant includes anions and polyatomic cations. Optionally, the polyatomic cations are selected from ammonium, phosphonium, arsenic, antimony, bismuth, and sulfonium. Optionally, the contact is performed under conditions where the covalent bonds between oxygen atoms and polyatomic cations on the surface of the substrate material are effective. Optionally, the method includes forming a suspension of a covalent network solid oxide material in an aqueous solution (such as water), and adding a linker precursor reactant to the suspension to form a mixture containing the precursor.

[0094] Optionally, such methods include subjecting the covalent network solid oxide material to ion exchange before contacting it with the linker precursor reactant. Optionally, the covalent network solid oxide material is subjected to ion exchange by suspending it in an aqueous solution (such as water) and contacting the suspension with an ion exchange resin. Optionally, the ion exchange resin is first washed by contacting it with deionized water, for example by passing deionized water through the ion exchange resin until the water becomes clear. Optionally, such methods include adding an ion linker portion in an amount providing a weight ratio of about 1:5 to about 1:0.04, such as about 1:4 to about 1:0.06, of the ion linker to the covalent network solid oxide material, such as the weight (in grams) of each material. Alternatively or additionally, such methods include adding the ion linker portion in an amount of about 80 mmol to 160 mmol per gram of covalent network solid oxide substrate material, such as about 100 mmol to about 140 mmol. Optionally, the substrate material is functionalized by reacting each oxygen atom on the surface of the substrate material with a carbon atom of a nucleophilically vulnerable linker precursor reactant to form a CO covalent bond. Optionally, the linker precursor reactant comprises a cation selected from N-[3-(trimethoxysilyl)propyl]-N,N,N-trimethylammonium, N-(trimethoxysilylpropyl)-N,N,N-trimethylphosphonium, and glycidyltrimethylammonium. Optionally, the substrate material is functionalized by reacting each oxygen atom on the surface of the substrate material with an epoxy group of the linker precursor reactant to form a CO covalent bond. Optionally, the linker precursor reactant comprises a glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each oxygen atom on the surface of the substrate material with an epoxy group of the glycidyltrimethylammonium cation to form a CO covalent bond. Optionally, the target gas is CO2.

[0095] Optionally, the adsorbent composition, adsorbent precursor, polyatomic cation, ionic compound (if present), and / or salt (if present) are as defined with respect to the adsorbent material of the first or third aspect of this disclosure and / or the adsorbent precursor of the second aspect of this disclosure.

[0096] According to a sixth aspect of the disclosed subject matter, a method for producing a carbon dioxide adsorbent is disclosed. The method may include providing an adsorbent support layer made of an oxide material; and reacting an ionic functional group with the support layer to form a trapping layer, the ionic functional group having at least one carbon dioxide adsorption site.

[0097] In some embodiments, providing an adsorbent carrier layer includes providing an oxide material suspension in solution; and wherein reacting ionic functional groups with the carrier layer as a trapping layer includes: passing the oxide material suspension through a cation exchange resin, performing ion exchange by adding the cation exchange resin to the solution, mixing glycidyltrimethylammonium chloride into the solution, and mixing anions into the solution.

[0098] In some embodiments, the oxide material suspension is in water, and approximately 5% wt is added to the solution.

[0099] In some embodiments, performing ion exchange includes adding a cation exchange resin to the solution at least four times.

[0100] In some embodiments, for every 1 gram of 5 wt.% oxide suspension, approximately 6 mmol of glycidyltrimethylammonium chloride is mixed into the solution.

[0101] In some embodiments, the oxide material suspension comprises or is selected from the group consisting of: aluminum oxide (Al2O3), silicon oxide (SiO2), cerium oxide (CeO2), zirconium oxide (ZrO2), and iron oxide (FeO2). x ), aluminosilicates, mesoporous oxide ceramics, and mixtures thereof.

[0102] In some embodiments, the oxide material suspension comprises or is a combination of materials selected from the group consisting of: aluminum oxide (Al2O3), silicon oxide (SiO2), cerium oxide (CeO2), zirconium oxide (ZrO2), and iron oxide (FeO2). x ), aluminosilicates and mesoporous oxide ceramics.

[0103] In some embodiments, the anion comprises or is selected from the group consisting of: carbonate, oxalate, phosphate, phosphite, sulfate, sulfite, sulfate, and borate.

[0104] In some embodiments, the anions are derived from ionic materials, such as alkali metal salts. Examples of alkali metal salts include sodium phosphate, sodium sulfite, sodium borate, and sodium carbonate.

[0105] It should be understood that the method of the sixth aspect of the disclosed subject matter may optionally incorporate any features described in relation to the method of the fourth or fifth aspect of the disclosed subject matter, and vice versa.

[0106] According to a seventh aspect of the disclosed subject matter, a method for removing a target gas from a gas stream is provided. Optionally, the gas stream has a first target gas concentration. Optionally, the method includes contacting the gas stream with an adsorbent composition under conditions effective for causing the adsorbent to adsorb the target gas, for example, thereby forming an adsorbent composition enriched with the target gas and a product gas stream having a second target gas concentration, for example, wherein the second target gas concentration is lower than the first target gas concentration. According to an eighth aspect of the disclosed subject matter, a method for removing a target gas from an adsorbent composition enriched with the target gas is provided. Optionally, the method includes contacting the adsorbent composition enriched with the target gas with the gas stream and water. Optionally, water is a component of the gas stream, for example, wherein the gas stream contains water vapor. Optionally, the gas stream has a relative humidity of at least 80%, such as at least 90%, for example, at least 99%. Optionally, the gas stream has a first target gas concentration. Optionally, the method includes contacting a gas stream with an adsorbent composition enriched with the target gas under conditions effective for causing the target gas to desorb from the adsorbent, for example, thereby forming a wetted adsorbent composition and a product stream (such as a product gas stream) having a second target gas concentration, for example, wherein the second target gas concentration is higher than the first target gas concentration. Optionally, the method includes separating the target gas from the product stream, and optionally treating the target gas to provide a target gas product suitable for use and / or storage.

[0107] Optionally, in such methods according to the seventh and / or eighth aspects of this disclosure, the adsorbent composition comprises a covalent network solid oxide substrate material functionalized with ion-linking moieties. Optionally, each ion-linking moieties comprises a polyvalent anion and a polyatomic cation, such as a polyatomic cation selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfonium. Optionally, the polyatomic cation is covalently bonded to oxygen atoms on the surface of the substrate material. Optionally, the target gas is CO2. Optionally, the adsorbent composition is as disclosed in the first or third aspect of the disclosed subject matter.

[0108] Optionally, the method of the eighth aspect of the disclosed subject matter (i.e., the method for removing the target gas from an adsorbent composition enriched with the target gas) further includes the step of drying the moistened adsorbent composition to form an adsorbent composition. Optionally, the drying step is performed once substantially all the target gas has been desorbed from the adsorbent material and / or once the product gas stream generated by contacting the moistened adsorbent material with a gas stream has a target gas concentration approximately the same as the target gas concentration of the gas stream. It should be understood that in such cases, no further target gas will be extracted from the adsorbent by continuous exposure to the gas stream. Optionally, such drying involves exposing the moistened adsorbent composition to a gas stream with a water content lower than the water content of the gas stream used to moisten the adsorbent composition. Optionally, the moistened adsorbent composition is dried by contacting it with a gas stream having a relative humidity of no more than about 60%, such as no more than about 50%, for example, no more than about 45%. Optionally, the step of drying the adsorbent composition produces an adsorbent composition according to the first or third aspect of the disclosed subject matter. Alternatively or alternatively, the step of drying the adsorbent may optionally provide a dried adsorbent composition comprising water, wherein the dried adsorbent composition comprises water in a smaller amount than that in a wet adsorbent composition. Optionally, the dried adsorbent composition comprises water, wherein the water is present in a water:polyvalent anion molar ratio of 1:10 to 40:1, such as 1:1 to 1:20.

[0109] According to the ninth aspect of the disclosed subject matter, a method for processing a gas stream is provided. Optionally, the method includes performing the method of the seventh aspect of the disclosed subject matter, and subsequently performing the method of the eighth aspect of the disclosed subject matter. Optionally, the method includes a drying step of performing the method of the eighth aspect of the disclosed subject matter, and subsequently repeating the method of the seventh aspect of the disclosed subject matter. Optionally, the method of the seventh aspect of the disclosed subject matter is thus repeated at least 5 times, such as at least 50 times, for example at least 500 times. Alternatively or additionally, the method includes reusing the adsorbent composition formed by drying, optionally without any further treatment or regeneration of the dried adsorbent composition.

[0110] According to a tenth aspect of the disclosed subject matter, a method for capturing carbon dioxide is disclosed. The method includes providing a humidity-wiggling adsorbent, the humidity-wiggling adsorbent being a material comprising: an adsorbent carrier layer made of a material comprising or selected from the group consisting of oxide nanoparticles and nanoporous materials; and a capture layer comprising an ion-modified material having at least one carbon dioxide adsorption site; exposing the humidity-wiggling adsorbent to a target gas; and wetting the humidity-wiggling adsorbent.

[0111] In some embodiments, the wetting humidity swing adsorbent includes collecting output water containing the released target gas.

[0112] In some embodiments, the method includes treating the output water to capture the target gas.

[0113] In some embodiments, the target gas is carbon dioxide.

[0114] In some embodiments, the method includes drying the humidity swing adsorbent and reusing the humidity swing adsorbent for subsequent exposure to the target gas.

[0115] It should be understood that the method of the tenth aspect of the disclosed subject matter may incorporate any features described in the methods of the seventh, eighth or ninth aspects of the disclosed subject matter, and vice versa.

[0116] According to the eleventh aspect of the disclosed subject matter, a porous membrane is provided for a device for separating a target gas from a gas stream. Optionally, the porous membrane comprises an adsorbent composition as disclosed in the first or third aspect of the disclosed subject matter. Optionally, the target gas is CO2. Optionally, the porous membrane contains an adsorbent composition. Optionally, the porous membrane is composed of an adsorbent composition, for example, wherein the adsorbent composition is in the form of a porous material through which the gas containing the target gas can pass. Alternatively, the porous membrane optionally comprises an adsorbent composition supported on a membrane material (such as a polymer membrane material), for example, wherein the adsorbent composition is incorporated into the porous membrane material.

[0117] According to the twelfth aspect of the disclosed subject matter, an apparatus for separating a target gas from a gas stream is provided. Optionally, the apparatus includes an adsorbent composition disclosed according to the first or third aspect of the disclosed subject matter. Optionally, the adsorbent composition is arranged to contact the gas stream. For example, the adsorbent composition may be provided in a channel configured to receive a gas stream containing the target gas. Optionally, the target gas is CO2. Optionally, the apparatus includes a porous membrane according to the eleventh aspect of the disclosed subject matter, for example, wherein the porous membrane comprises or is composed of an adsorbent material. Optionally, the apparatus includes an air movement device (such as a fan) for contacting the gas stream with the adsorbent composition (e.g., for transporting the gas stream along or through the channel where the adsorbent material is located). Optionally, the apparatus includes a wetting device for wetting the adsorbent material, such as a sprayer, a fine atomizer, or an evaporator. Optionally, the wetting device adds moisture to the gas stream to contact the adsorbent material. Alternatively or alternatively, the wetting device may spray water directly or otherwise deposit water onto the adsorbent material. Optionally, the apparatus includes a heater, for example, to assist in drying the adsorbent material. Optionally, such heaters are configured to heat the gas stream used to contact the adsorbent material and / or directly heat the adsorbent material, for example, by thermal radiation or thermal conduction. Alternatively, the apparatus may not have a heating element, for example, in which the apparatus is configured to dry the adsorbent material by contacting it with an ambient temperature gas stream having suitable humidity. Attached Figure Description

[0118] Figure 1 shows the adsorption and desorption timelines of existing polymer resin-based adsorbents.

[0119] Figure 2 Images of ceramic oxide particulate materials according to some variations of this disclosure and TEM images of said particulate materials are shown.

[0120] Figure 3 The graph shows the CO2 adsorption and desorption properties of some variants of the oxide-based humidity swing adsorbent according to this disclosure.

[0121] Figure 4 A graph showing five cycles of CO2 capture and desorption for some variants of the oxide-based humidity swing adsorbent according to this disclosure.

[0122] Figure 5 This is a schematic diagram of an exemplary system operating in CO2 capture mode, desorption mode, and descaling mode.

[0123] Figure 6 , Figure 7 and Figure 8 A flowchart of a method variant for producing a humidity-oscillating adsorbent.

[0124] Figure 9 , Figure 10 , Figure 11 and Figure 12 A flowchart of a variation of a method for capturing CO2 using a humidity-controlled oscillating adsorbent.

[0125] Figure 13 This illustration illustrates a humidity-swirling adsorbent variant with an oxide nanoparticle carrier layer, the oxide nanoparticle carrier layer having a trapping layer of ion-modified material bonded around the surface of the oxide nanoparticles.

[0126] Figure 14 This illustration shows a humidity-swirling adsorbent variant with a nanoporous support layer containing an ion-modified material with a trapping layer within the pores.

[0127] Figure 15 and Figure 16 A graph comparing the energy of humidity-swirling adsorbent variants with other capture technologies.

[0128] Figure 17A A schematic diagram illustrating the adsorption of carbon dioxide associated with the hydrated ring around the anion under dry conditions, according to some variations of this disclosure.

[0129] Figure 17BThis is a schematic diagram illustrating the desorption of carbon dioxide associated with the decomposition of the hydrated ring around the anion under humid conditions, according to some variations of this disclosure.

[0130] Figure 18 The diagram below illustrates ion pairs on oxide nanoparticles according to some variations of this disclosure, wherein the spacing between anions is suitable for forming a hydrated shell.

[0131] Figure 19 The diagram illustrates ion pairs contained within the pores of a nanoporous / mesoporous structure, according to some variations of this disclosure, wherein the spacing between the anions is adapted to form a hydrated shell. Detailed Implementation

[0132] The following description of embodiments of this application is not intended to limit the disclosed subject matter to these embodiments, but is intended to enable those skilled in the art to implement and use the disclosed subject matter.

[0133] 1. Overview

[0134] The compositions, methods, and systems of humidity-controlled oscillating adsorbents described herein use ion-functionalized materials to capture and controllably release selected target gases.

[0135] In particular, the compositions, methods, and systems described herein can be used to capture carbon dioxide (CO2) from the air, followed by controlled release using humidity oscillation. The compositions, methods, and systems can alternatively or additionally be used to capture and release target gases such as sulfur dioxide (SO2), hydrogen sulfide (H2S), and nitrogen oxides (NOx). x (e.g., nitric oxide NO and nitrogen dioxide NO2). In this document, humidity-swiveling adsorbents are primarily described in the context of CO2 capture and release, using examples of CO2 capture and release, but the compositions, methods, and systems are not limited to CO2 and are similarly applicable to the capture of other target gases.

[0136] Humidity-wobbling adsorbents are preferably ion-functionalized materials, and in some variants, they can be fabricated using a nanoparticle support layer or a support layer with a nanoporous / mesoporous structure. The humidity-wobbling adsorbent uses a support layer as a structural framework on which a trapping layer made of ion assemblies—more specifically, ion pairs (e.g., a combination of multiple cations and multiple anions in a certain ratio, which may be generally neutrally charged)—can be arranged in space to facilitate the chemical capture and release of carbon dioxide via humidity wobbling. Ion pairs can be spatially distributed using the support layer as a scaffold, such that the ion pairs, and more specifically the anions of the ion pairs, are appropriately spaced to form a hydrated shell around each anion. Alternatively, the anions can be spaced at an amorphous distance, characterized by a distance greater than the diameter of the hydrated shell. For example, the spacing between anions can also be referred to as displacement. In some variants, the hydrated shell can have one to three layers. In some variants, the displacement can be greater than some displacements in the range of 1 Å to 15 Å. In a single-layer hydrated shell, the displacement between anions (e.g., different ion pairs) can be greater than 2 Å to 3 Å. In a two-layer hydrated shell, the displacement between anions (e.g., different ion pairs) can be greater than 3 Å to 5 Å. In a three-layer hydrated shell, the displacement between anions (e.g., different ion pairs) can be greater than 10 Å to 15 Å.

[0137] For example, anions can be spaced apart by bonding or grafting around nanoparticles to allow CO2 to interact with the adsorbent through interaction with the hydrated shell. This spacing allows CO2 to react to form bicarbonate ions trapped within the hydrated shell. However, when the number of water molecules reaches a certain level (e.g., greater than 10 to 40 water molecules), the conditions become ineffective, causing bicarbonate ions to recover and releasing the resulting CO2 into the solution (e.g., water). When the adsorbent returns to dry conditions, the hydrated shell can reform around the anions to capture CO2 again.

[0138] The support layer materials used in the adsorbent, including nanoparticles and / or nanoporous materials, can achieve large surface areas and structures, thereby providing enhanced channels for CO2 and H2O transport. In one variant, oxide-based nanoparticles can be used as the support layer, wherein the trapping layer is bonded around the oxide nanoparticles, such as... Figure 13 As shown in the figure. Additionally, nanoparticles (NPs, with diameters ranging from 1 nm to 1000 nm) can have fully exposed surfaces, resulting in extremely high surface areas. Furthermore, nanoparticles can serve as scaffolds to which cations of ion pairs can be grafted or otherwise bonded to force the geometric spacing of anions, suitable for forming a hydrated shell around the anions. Figure 2TEM images of ceramic materials according to some embodiments of the present disclosure are shown. In other variations, the support layer may be a nanoporous material (e.g., pore size from 1 nm to 1000 nm), and in some cases, a mesoporous material (e.g., pore size of 2 nm and 50 nm). Figure 14 As shown in the example diagram, in a carrier layer made of nanoporous / mesoporous materials, the ion-modifying material of the trapping layer can be contained within the pores of the porous material.

[0139] Compositions, methods, and systems can utilize humidity-oscillating adsorbents in a variety of direct air capture applications. Humidity-oscillating ion-functionalized materials within the humidity-oscillating adsorbent can be used to capture CO2 (and other acidic gases) from the air under dry conditions and release CO2 under humid conditions (humidity oscillation), such as... Figure 5 As shown in the diagram, under dry conditions, a hydrated shell forms around anions of ion pairs (spaced together via a support structure of several carrier layers). Exposure of carbon dioxide to the anions and the hydrated shell will trigger a reaction to form bicarbonate (HCO3-). - In some embodiments, the loaded adsorbent can be regenerated by washing with water. Introducing a large number of water molecules results in water acting as a bulk water molecule. Therefore, when the number of water molecules near the ion pair becomes sufficiently large (e.g., >10, >20, >30, >40, or even >50), the hydration shell decomposes. The decomposition of the hydration shell results in the release of chemically captured carbon dioxide (in the form of bicarbonate). In some embodiments, the adsorbent can be dried in air so that it can reabsorb the target gas. When dried, the hydration shell can reform around the ion pair and then capture CO2 again.

[0140] The capture or release process of the adsorbent can be driven by inexpensive water. When the humidity in the air is low, the adsorbent can capture CO2. When the adsorbent is partially or fully loaded, it can be placed in water (or another wetting solution) and CO2 is released. The released CO2 can be collected or treated. For example, CO2 can be prepared for storage or other applications. In one instance, the collected CO2 can be used in greenhouses, the cement industry, flower / fruit transportation, synthetic fuel production, and / or other applications.

[0141] Systems and methods can provide several potential benefits. Systems and methods are not limited to always providing such benefits, and are presented only as exemplary representations of how said systems and methods can be used. The list of benefits is not exhaustive, and other benefits may exist additionally or alternatively.

[0142] As a potential benefit, the compositions, methods, and systems provide adsorbents particularly suitable for direct air capture applications. Some preferred variants of the adsorbent can directly capture CO2 from ambient air. Additionally, the adsorbent can be highly selective. In particular, some variants of the adsorbent can only capture CO2 from the air and not H2O.

[0143] As another benefit, the compositions, methods, and systems utilize humidity-wobbling adsorbents that employ a chemical reaction to capture carbon dioxide. Introducing water into the adsorbent reverses the chemical reaction that binds carbon dioxide to the adsorbent. Using these compositions, methods, and systems avoids the problems encountered with physisorption adsorbents. For example, humidity-wobbling adsorbents avoid the simultaneous, excessive water capture that occurs in many other adsorbents. In particular, systems utilizing long-chain amines (such as polyethyleneimine, PEI) tend to adsorb large amounts of water. Conversely, some variations of this disclosure use oxide materials as a structural framework to achieve a scaffold with a desired surface area to expose the ion-modified material of the capture layer.

[0144] As another potential benefit, the compositions, methods, and systems can use adsorbents that exhibit excellent stability. In some variants, humidity-swirling adsorbents experience minimal or no degradation after 10,000 cycles.

[0145] As another potential benefit, the compositions, methods, and systems can achieve rapid kinematics during the capture and release of target gases such as CO2. As illustrated by exemplary data in Figure 1, the adsorption and desorption time range of previous polymer-based resin adsorbent materials could exceed ten hours for prior resin-based humidity-wiggling adsorbents. Accordingly, the material limitations of such resins severely restrict the practical feasibility of such solutions. Figure 3 As shown, the variant adsorbent materials described herein can exhibit significantly faster adsorption and desorption time ranges of less than one hour in some cases (e.g., in...). Figure 3 In the experimental example shown, it was approximately 50 minutes. Accordingly, this could mean that the humidity-oscillating adsorbent could cycle many more times within a given time period. For example, Figure 4 Five cycles of CO2 capture and release of the adsorbent variant described herein are shown.

[0146] As a potential benefit, the compositions, methods, and systems can enable highly energy-efficient solutions for capturing target gases such as CO2. In some instances, the humidity-swiveling adsorbents described herein can have an adsorption energy cost that is a fraction (e.g., 35% or less) of other comparable existing adsorbents. Figure 15 and Figure 16As shown, compared to competing technologies, the water-driven humidity oscillating adsorbent described herein exhibits high energy efficiency and good stability. Furthermore, in addition to its high energy efficiency, the humidity oscillating adsorbent does not consume heat during regeneration, which is considered a significant bottleneck to the high energy costs of traditional direct air capture technologies. Compared to traditional amine solutions, the energy cost may be one-third or less (e.g., less than or equal to 33%). Compared to traditional strongly alkaline solutions, the energy cost may be one-sixth or less (e.g., less than or equal to approximately 17%).

[0147] For example, Ca-based calcination processes and Na-based decomposition and hydrolysis processes have adsorption heats of 179 kJ / mol CO2 and 135 kJ / mol CO2, respectively. Based on the average reported adsorption heat of CO2 adsorption in amine solutions, the average reported adsorption heat of amine-based adsorbents is estimated to be approximately 80 kJ / mol to 120 kJ / mol CO2. In contrast, the humidity-controlled oscillating adsorbent of this disclosure exhibits an energy cost of 32 kJ / mol CO2 for adsorbent regeneration. Optionally, the adsorbent compositions of the disclosed subject matter provide energy usage of no more than about 50 kJ / mol captured CO2, such as carbon capture systems with no more than about 40 kJ / mol captured CO2.

[0148] As another potential benefit, from a financial perspective, the compositions, methods, and systems can serve as cost-effective solutions. Both capital and operating expenditures are cost-effective. In some embodiments, the cost of capturing CO2 can be less than $100 per tonne of CO2. As a factor contributing to the cost-effectiveness of the solution, humidity-swept CO2 adsorbents use inexpensive water and require no additional heat. As another contributing factor, the stability of the adsorbent also helps reduce operating costs.

[0149] As another potential benefit, the compositions, methods, and systems are designed to be scalable solutions, enabling them to scale to extremely large scales while remaining cost-effective. This scalability is crucial for becoming an effective solution to the world's environmental problems.

[0150] 2. Composition

[0151] An adsorbent composition may include: an adsorbent support layer; and a trapping layer comprising an ion-modifying material. The ion-modifying material preferably has at least one target gas adsorption site thereon. Such compositions can be used as adsorbents for adsorbing target gases. In particular, such compositions or variants described herein can be used for adsorbing carbon dioxide, but may also be used alternatively or alternatively for other target gases such as SO2, H2S, and NO. x .

[0152] Accordingly, in some variants, the adsorption sites can be carbon dioxide adsorption sites. In this way, the adsorbent can undergo a humidity swing chemistry reaction, wherein, in a dry state, the adsorbent adsorbs CO2 by converting it to bicarbonate in the presence of a gas stream, while in a humid state, the adsorbent releases CO2 and the capture layer reverts to an ion-modified material upon returning to a dry state. In some alternative variants, the multiple adsorption sites can be sulfur dioxide adsorption sites, hydrogen sulfide adsorption sites, or nitrogen oxide adsorption sites. In this document, the compositions are primarily described in the context of CO2 capture, but the compositions can be alternatively modified and / or used to capture other target gases.

[0153] The ion-modified material is preferably a combination of positively charged ions (cations) and negatively charged ions (anions). The positively charged ions and negatively charged ions are preferably implemented in the form of ion pairs. An ion pair can be a neutral equilibrium combination of at least one cation and at least one anion. For example, a neutral ion pair can be two glycidyltrimethylammonium (GTA) groups. + ) cation and one carbonate ion (CO3) 2- The anions of the ion pairs can facilitate chemical bonding with carbon dioxide under dry conditions. This chemical bonding reaction that induces carbon dioxide adsorption occurs when the number of water molecules near the anions of the spacer ion pairs is sufficiently low (e.g., under dry conditions). CO2 may be released during exposure to humid conditions (e.g., exposure to water). This capture and release may be caused by interactions with a hydrated shell formed around the spatially isolated anions in the adsorbent structure. The anions can be spatially isolated (e.g., sufficiently spaced) because the ion pairs are bonded or grafted onto nanoparticles in a spaced-apart manner (e.g., ...). Figure 18 (as shown) or by controlling ion pairs within the pores of nanoporous materials (such as... Figure 19 As shown in the image).

[0154] As a variant, the support layer can be a support layer made of oxide material as a scaffold for the trapping layer. In such oxide variants, the composition of the adsorbent for adsorbing carbon dioxide may include: an adsorbent support layer made of oxide material; and a trapping layer comprising an ion-modified material having at least one carbon dioxide adsorption site thereon.

[0155] More specifically, in some variations, the composition of the adsorbent for adsorbing carbon dioxide may include: an adsorbent support layer made of an oxide material; and a trapping layer comprising a set of neutral ion pairs having at least one cation and at least one anion, wherein the set of neutral ion pairs are spatially distributed through a support of oxide material such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is a carbon dioxide adsorption site.

[0156] Oxide variants of adsorbents can include nanoparticle variants and nanoporous variants of adsorbents.

[0157] In the nanoparticle variant, the support layer is made of oxide nanoparticle material, wherein an ion-modified material is bonded around the surface of the nanoparticles of the oxide nanoparticle material. In the variant with the nanoparticle material support layer, a set of neutral ion pairs spatially distributed on the scaffold of the oxide material can be spaced apart by each cation in at least one of the cations spatially grafted onto the oxide nanoparticles of the oxide nanoparticle material. The cations will be grafted or otherwise bonded around the oxide nanoparticles, and the anions will be bonded to the cations. The arrangement of the cations grafted onto the nanoparticles will force the anion spacing of the ion pairs. It should be understood that the spacing of the cations can be achieved, for example, by controlling the concentration of cations in the solution used to treat the oxide material. For example, cations may tend to avoid grafting onto the oxide material at sites very close to each other, thus favoring a larger spacing between cations at lower cation concentrations in the solution.

[0158] Accordingly, in some variations, the composition of the adsorbent for adsorbing carbon dioxide may include: an adsorbent carrier layer made of an oxide material; and a trapping layer comprising a set of neutral ion pairs having at least one cation and at least one anion, wherein each cation of the at least one cation of the set of neutral ion pairs is spatially grafted onto the oxide nanoparticles of the oxide nanoparticle material, such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is a carbon dioxide adsorption site.

[0159] Multiple neutral ion pairs can be grafted onto the same nanoparticle of the oxide nanoparticle material. The neutral ion pairs are preferably spatially grafted onto or around the oxide nanoparticle, such that the anions of the neutral ion pairs are sufficiently spaced apart. In some variations, the spacing between the anions can be characterized as amorphous spacing, where the anions do not exhibit crystalline forms. In this way, the anions can serve as suitable sites for forming a hydration shell. The spacing between the anions can be larger than the diameter of the hydration shell to reserve space for its formation.

[0160] Oxide variants of the adsorbent may also include nanoporous or, more specifically, mesoporous oxide materials. In nanoporous / mesoporous variants, the ion-modifying material of the trapping layer may be contained within the pores of the nanoporous oxide material.

[0161] As another variant, the support layer may be made of a nanoporous material, which may be made of oxide materials and / or other non-oxide nanomaterials. In such porous variants, the composition of the adsorbent for adsorbing carbon dioxide may include an adsorbent support layer made of a nanoporous material; and a trapping layer comprising an ion-modified material having at least one carbon dioxide adsorption site thereon, and the ion-modified material being contained within the pores of the nanoporous material.

[0162] More specifically, the composition of the adsorbent for adsorbing carbon dioxide may include an adsorbent carrier layer made of a nanoporous material; and a trapping layer comprising a set of neutral ion pairs having at least one cation and at least one anion, wherein the set of neutral ion pairs is contained in the pores of the oxide nanoporous material such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is an adsorption site for the target gas (e.g., carbon dioxide).

[0163] The ion pairs are preferably physically contained and isolated within individual pores. The number of ion pairs present in each pore can be adjusted so that the anions of different ion pairs are sufficiently separated. It should be understood that such adjustment can be achieved, for example, by controlling the concentration of the ion-functionalized material when the support layer is treated with a solution of the ion-functionalized material.

[0164] Similar to the nanoparticle variants, the support layer acts as a scaffold to facilitate conditions for anion separation, thereby enabling the formation of a hydrated shell. In some variants, when fewer than 20 anions are present in the pores, the neutral ion pairs contained in the pores of the oxide nanoporous material have an amorphous spacing between the anions to form a hydrated shell. However, the number of anions in each pore may depend in part on the pore size.

[0165] In this paper, the support layer is described as a porous nanoporous material. The pores may be substantially spherical in morphology, but can alternatively be tubular, irregular, or of any suitable shape. The pores preferably have a certain nanoscale confinement size to help limit the concentration of ion pairs and promote the formation of a hydration shell. For example, the pore openings preferably have a maximum diameter of no more than about 15 angstroms, such as no more than about 12 angstroms. Alternatively, the pore openings preferably have a maximum diameter of about 8 to 15 angstroms, such as about 10 to 12 angstroms.

[0166] In such nanoporous variants, the support layer can be or includes nanoporous materials, such as oxide nanoporous materials and various other nanoporous materials. Accordingly, the support layer can be nanoporous materials such as aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), and iron oxide (FeO₂). x ), aluminosilicates, mesoporous ceramics, activated carbon, quartz, zeolite, carbon nanotubes, organometallic frame (MOF) materials and / or covalent organic frame (COF) materials.

[0167] The support layer acts as a structural scaffold for the ion-modifying material of the trapping layer. The support layer can provide a structural basis so that the ion pairs have a spacing suitable for forming a hydrated shell, and can also enhance the exposure to gases for chemical trapping of target gases such as carbon dioxide (e.g., by providing a high surface area).

[0168] The support layer may include structural features of the material that enhances exposure to the target gas and its formation. Accordingly, in some variations, the support layer may be made of a material having a nanoporous or more specifically mesoporous structure. In some alternative variations, the support layer may be made of nanoparticle materials.

[0169] In some variants, ceramic materials (including nanoporous / mesoporous materials and oxide nanoparticles) can exhibit a scaffold structure, enabling a large exposed surface area. Such material structures within the support layer can provide enhanced channels for CO2 and H2O transport. Air (e.g., air used for direct air capture or industrial gas streams) can preferably be exposed to the surface area of ​​the adsorbent having such a support layer. Water can similarly contact a large surface area of ​​the adsorbent during carbon dioxide desorption. Variants using nanoparticles (NPs) with diameters ranging from 1 nm to 1000 nm can similarly possess a highly exposed surface and extremely large surface area. Such structural qualities can have beneficial effects on the kinematics of the adsorbent when used as a humidity-swirling adsorbent.

[0170] As described above, in one variant, the support layer can be made of or comprise an oxide material. The oxide material support layer can be used as a nanoporous / mesoporous oxide material or as an oxide nanoparticle material. As a porous material, an ion-modified material, more specifically, ion pairs can be contained within the pores of the nanoporous / mesoporous oxide material, such as... Figure 19As shown in the diagram. In another variant, the oxide material support can be oxide nanoparticles, where the adsorbent is an aggregate of such nanoparticles. In the nanoparticle variant, the support layer comprises an aggregate of oxide nanoparticles, and ion-modified materials (more specifically ion pairs) can be bonded around the surface of the oxide nanoparticles, such as... Figure 18 As shown in the figure, oxide materials can be materials that are easily attached to or grafted with ionic modified materials by cationic materials.

[0171] In some variations, the oxide material can be a ceramic material. It should be understood that a ceramic material can be an inorganic non-metallic solid that has been shaped and then hardened (and / or densified) by heating to a high temperature. Typically, ceramic materials are characterized by their hardness, corrosion resistance, chemical inertness, and brittleness. Ceramic materials can be crystalline, glassy, ​​or both crystalline and glassy. In some variations, the oxide material can be oxides such as: aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), and iron oxide (FeO₂). x And / or aluminosilicates. Accordingly, the oxide material may comprise or be selected from the group consisting of: aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), iron oxide (FeO₂) and / or aluminosilicates. x ( ) and / or aluminosilicates. This may include nanoparticle variants and / or nanoporous or mesoporous variants thereof. Oxide materials may additionally or alternatively be selected from the group that also includes aluminosilicates, mesoporous ceramics and / or their associated nanoparticles.

[0172] In some variations, the support layer may be made of a combination of oxide materials. Accordingly, the support layer may be made of a combination of oxide materials comprising or selected from the group consisting of: aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), and iron oxide (FeO₂). x ) as well as aluminosilicates and mesoporous ceramics and / or their related nanoparticles.

[0173] In nanoporous variants of the support layer, the support layer can be made of or comprise a material other than an oxide material, or an alternative to an oxide material. For example, the support layer can be made of or comprise a material such as activated carbon, quartz, zeolite, carbon nanotubes, organometallic framework (OFM) materials, and covalent organic framework (COF) materials. In one example, quartz (e.g., silica SiO2) can be used as the oxide material in the support layer. In another example, zeolite (e.g., a microporous crystalline aluminosilicate material) can be used as the material in the support layer. Accordingly, the nanoporous material can be a material comprising, selected from, or a combination of materials selected from the group consisting of: activated carbon, quartz, zeolite, carbon nanotubes, organometallic framework materials, and covalent organic framework materials.

[0174] The role of the trapping layer is to construct ionic functional groups within or around the structure of the carrier layer. More specifically, anionic functional groups can be constructed for the chemisorption and desorption of carbon dioxide depending on the state of humidity swing (e.g., dry or humid conditions). The anion is preferably part of an ion pair, and more specifically, part of a neutral ion pair. The ion pair may include at least one cation and at least one anion. In some embodiments, the ratio of cation to anion is 1:1. In some embodiments, the ratio of cation to anion is not 1:1. The ion pair is preferably neutral, although some variations may include charge imbalance. In one example, the neutral ion pair may be two glycidyltrimethylammonium (GTA) groups. + ) cation and one carbonate anion (CO3) 2- ).

[0175] The adsorption sites can be carbon dioxide adsorption sites, but the trapping layer can alternatively use ion-modified materials to construct a structure targeting one or more other target gases (such as SO2, H2S, and NO). x The adsorption sites for anions can be formed around them. A hydrated shell can be formed around each anion of a set of ion pairs to serve as an adsorption site, wherein the adsorption site (or more specifically, the hydrated shell) around each anion is conditioned by humidity conditions.

[0176] In some embodiments, when under hydrated shell conditions based on the number of water molecules, the presence of carbon dioxide drives a first reaction between carbon dioxide, the hydrated shell, and anions to form at least bicarbonate ions within the hydrated shell.

[0177] In some embodiments, the hydration shell condition based on the number of water molecules is when the number of water molecules is less than 50 per anion. In some embodiments, the hydration shell condition based on the number of water molecules is when the number of water molecules is less than 30 per anion. In some embodiments, the hydration shell condition based on the number of water molecules is when the number of water molecules is less than 20 per anion. In some embodiments, the hydration shell condition based on the number of water molecules is when the number of water molecules is less than 10 per anion.

[0178] In some embodiments, when the hydrated shell decomposes under conditions based on the number of water molecules, the hydrated shell decomposes through a second reaction that releases CO2 from bicarbonate ions into an aqueous solution (e.g., water).

[0179] In some embodiments, the condition for hydration shell decomposition based on the number of water molecules is when the number of water molecules is greater than 50 per anion. In some embodiments, the condition for hydration shell decomposition based on the number of water molecules is when the number of water molecules is greater than 30 per anion. In some embodiments, the condition for hydration shell decomposition based on the number of water molecules is when the number of water molecules is greater than 20 per anion. In some embodiments, the condition for hydration shell decomposition based on the number of water molecules is when the number of water molecules is greater than 10 per anion.

[0180] Positively charged ions (cations) can be such as sodium ions (Na+). + ), potassium ions (K) + ) and / or GTA + The cation. Accordingly, the cation may include or be selected from Na. + K + and glycidyltrimethylammonium (GTA) + The ions consist of a positively charged group (i.e., the cation group). The negatively charged ions (anions) may include or be selected from carbonate (CO3) ions. 2- ), oxalate (C2O4) 2- ), phosphate (PO4) 3- ), phosphate (PO3) 2- ), sulfate (SO4 2- ), sulfite (SO3) 2- ), silicate (SiO4) 4- ) and borate (BO3) 3- A cation is a group of negatively charged ions (i.e., anions). In some variations, anions can be a combination of different types of anions selected from the negatively charged ion group. Similarly, a cation can be a combination of different types of cations selected from the positively charged ion group.

[0181] In some variations, corresponding anionic salts may be used. Accordingly, the ion-modifying material may be or include a combination of multiple ion-modifying materials comprising or selected from the group consisting of salts of sodium phosphate, sodium phosphite, sodium sulfite, sodium sulfate, sodium borate, sodium oxalate, and sodium carbonate. Other suitable anionic materials or salts may be used alternatively.

[0182] In the presence of a gas stream, the adsorbent can preferably adsorb CO2 and convert it into bicarbonate (HCO3-). - The formation of bicarbonate ions can be accompanied by the protonation of the anions in the ion pair, such as HC₂O₄. - HPO4 2- HPO3 - HSO4 - HSO3 - HSiO4 3- HBO3 2- Or another HCO3 - Therefore, anions can capture and retain CO2 until exposure to H2O, at which point CO2 can be released. Drying the adsorbent after washing preferably resets the adsorption sites. Accordingly, in the dry state, the adsorbent will adsorb CO2 by converting it into protonated forms of bicarbonate and anions in the presence of a gas stream, while in the wet state, the adsorbent releases CO2, and the capture layer reverts to an ion-modified material upon returning to the dry state. This capture and release may be at least partially driven by the presence of a stable hydration shell. As discussed, when the water concentration in the material environment is appropriate and the ion pairs are appropriately spaced, the hydration shell may be around the ions of the ion pairs.

[0183] Adsorbents can capture or release carbon dioxide based on the humidity state of the environment surrounding the adsorbent material, which affects the conditions under which water molecules form a hydration shell or exhibit bulk water (e.g., aqueous water). Accordingly, when conditions for hydration shell formation (which can be based on the number of water molecules per anion) are present, the presence of carbon dioxide drives the initial reaction between carbon dioxide, water molecules in the hydration shell, and anions to form bicarbonate ions and protonated forms of anions within the hydration shell, such as... Figure 17A As shown in the image.

[0184] The conditions for a hydrated shell based on the number of water molecules can be when the number of water molecules is less than 50 per anion, less than 40 per anion, less than 30 per anion, less than 20 per anion, and / or less than 10 per anion, depending on the exact implementation. For example, in some variations, a hydrated shell may occur when there are fewer than 10 interacting water molecules per anion.

[0185] The conditions for the decomposition of the hydrated shell can be similarly based on the number of water molecules per anion. Under these conditions, the hydrated shell decomposes through a second reaction that releases CO2 from bicarbonate ions into an aqueous solution (e.g., water), as... Figure 17B As shown in the image.

[0186] The conditions for the decomposition of the hydration shell can be greater than 50, 40, 30, 20, and / or 10 water molecules per anion, depending on the specific implementation. For example, in some variations, the hydration shell can decompose to release captured CO2 when more than 10 water molecules per anion interact to make the water appear as bulk water. It should be understood that the number of water molecules per anion suitable for forming a stable hydration shell can depend on the ionic material (e.g., the anion) and / or on the carrier layer.

[0187] In one example, the humidity swing adsorbent uses a support layer made of SiO2 nanoparticles and uses GTA... + A trapping layer of ion pairs consisting of cations and carbonate anions. In this exemplary variant, carbon dioxide can be trapped based on the humidity swing transition under dry conditions according to the following reaction: (where n is the amount of water, also known as the number of water molecules per anion).

[0188] dry: .

[0189] Furthermore, based on the following reaction, the humidity swing transition under humid conditions will be able to release the adsorbed carbon dioxide:

[0190] Moist: .

[0191] In similar examples, nanoporous adsorbents and humidity-wiggling adsorbents use a support layer made of nanoporous materials (such as COF or MOF) and use GTA. + A trapping layer of an ion-modified material consisting of a combination of cations and carbonate anions. In this variant, at least one anion of the ion pair is carbonate. In this exemplary variant, carbon dioxide can be similarly trapped based on the humidity swing transition under dry conditions according to the following reaction:

[0192] dry: .

[0193] Furthermore, based on the following reaction, the humidity swing transition under humid conditions will be able to release the adsorbed carbon dioxide:

[0194] Moist: .

[0195] When moist, bicarbonate ions revert to releasing CO2 and carbonate anions in the ion pair.

[0196] In another variant, at least one anion is sulfite ion (SO32-). 2- This anion drives the reaction similarly under both dry and humid conditions. The first reaction (under hydrated shell conditions) is characterized by:

[0197]

[0198] Furthermore, the characteristics of the second reaction may be:

[0199] .

[0200] In some embodiments, at least one anion is a phosphate ion (PO3). 3- This anion drives the reaction similarly under both dry and humid conditions. The first reaction (under hydrated shell conditions) is characterized by:

[0201]

[0202] Furthermore, the characteristics of the second reaction may be:

[0203] .

[0204] In some embodiments, at least one anion is a phosphate ion (PO4). 3- This anion drives the reaction similarly under both dry and humid conditions. The first reaction (under hydrated shell conditions) is characterized by:

[0205]

[0206] Furthermore, the characteristics of the second reaction may be:

[0207] .

[0208] It should be understood that, in some embodiments, at least one anion is borate (BO3). 3- ), oxalate (C2O4) 2- ), silicate (SiO4) 4- ) or sulfate (SO4) 2- Anions can drive reactions under dry and humid conditions similarly to the first reaction (under hydrated shell conditions) and the second reaction corresponding to the reactions disclosed above.

[0209] 3. Method for producing adsorbent compositions

[0210] A method for producing a humidity-oscillating adsorbent may include: providing an adsorbent support layer S110; and reacting or grafting ionic functional groups onto the support layer S120, such as... Figure 6 As shown in the diagram, ionic functional groups can be reacted or grafted to form a capture layer, which may have at least one adsorption site. The capture layer will preferably include adsorption sites distributed on the support layer. This adsorption site can be a carbon dioxide capture site or a capture site for any other type of target gas.

[0211] The method described herein can be used to produce humidity-swirling adsorbents, including any adsorbent variants described herein. In this way, the support layer and ionic functional groups (e.g., various ion-modified materials for the trapping layer) can be any materials described herein and / or include any properties described herein.

[0212] In one variant, a method for producing an adsorbent for capturing carbon dioxide using a humidity-swirling material may include: providing an adsorbent support layer made of an oxide material (S110); and reacting ionic functional groups with the support layer as a carbon dioxide capturing layer (S120). This method can be used to form an adsorbent having a nanoporous or mesoporous support layer. This method can also be used to form an adsorbent having a support layer made of an oxide material, such as oxide nanoparticles.

[0213] In another variant, a method for producing an adsorbent for capturing carbon dioxide using a humidity-swirling material may include: providing an adsorbent support layer made of a porous material (S110); and reacting ionic functional groups with the support layer as a carbon dioxide capturing layer (S120). This method can be used to form an adsorbent having a nanoporous or mesoporous support layer, which may be made of oxide materials and some non-oxide materials, such as activated carbon, quartz, zeolite, carbon nanotubes, metal-organic framework (MOF) materials, and covalent organic framework (COF) materials.

[0214] Multiple production processes can be used to produce humidity-oscillating adsorbents. Figure 7In one embodiment of the method shown, the production of the humidity-wiggling adsorbent may include: providing an adsorbent support layer S110 comprising an oxide material suspension S111 provided in solution; and reacting or grafting ionic functional groups with the support layer as a trapping layer S120 may include: washing a cation exchange resin with deionized water S121; performing ion exchange by adding the cation exchange resin to the solution S122; mixing glycidyltrimethylammonium chloride into the solution S123; and mixing a salt containing anions into the solution S124. Without being bound by theory, it is believed that in the step of mixing GTAC with the solution (S123), GTAC reacts with oxygen-containing groups on the oxide surface, thereby grafting GTAC onto the oxide. More specifically, hydroxyl groups on the oxide surface can react with the epoxy groups of GTAC, opening the ring and forming an OC covalent bond between the oxide surface and GTAC. It is further believed that when a salt contains anion (such as an alkali metal salt, e.g., sodium carbonate), the anion (e.g., carbonate ion) is replaced by chloride (e.g., forming sodium chloride), causing the anion to bind to the surface-bonded GTA. + Cations form "ion pairs" (e.g., in the case of carbonate, where the "ion pair" consists of two surface-bonded GTAs). + (Composed of a functional group and an anion). Chlorine-containing salts (e.g., sodium chloride) can then be separated, for example, by retaining them in solution during the extraction of the functionalized adsorbent material.

[0215] like Figure 8 As shown, in one example, such a process can be implemented more specifically such that a variation of the method for producing the adsorbent includes: providing a 5% wt suspension of the oxide material in water (S111); flushing the cation exchange resin with deionized water until clear water is collected, thereby washing the cation exchange resin (S121); performing ion exchange by adding the cation exchange resin to the oxide-containing solution four times (S122); mixing 6 mmol of glycidyltrimethylammonium chloride for every 1 gram of the oxide solution prepared in solution (S123); stirring the solution; mixing anions into the solution in the form of a salt (such as an alkali metal salt) (S124); and centrifuging the solution. The centrifugation step separates the functionalized adsorbent material from the aqueous solution and thus also from highly soluble chlorine-containing salts (e.g., sodium chloride).

[0216] Box S110 provides an adsorbent support layer, which serves to construct the adsorbent support layer. In some variations, the support layer is a nanoporous material or more specifically a mesoporous material having a corresponding nanoporous or mesoporous structure. For example, the support layer can be made of a ceramic material, which is a nanoporous material or more specifically a mesoporous oxide material. In particular, the nanoparticles can be oxide nanoparticles. In some variations, the support layer includes or is made of nanoparticle materials.

[0217] In some variations, the support layer may include materials such as aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), and iron oxide (FeO₂). x These are materials or combinations thereof, including aluminosilicates, and are made from or related to aluminosilicates. Such oxide materials can be used in nanoporous or mesoporous forms. Alternatively, oxide nanoparticles can be provided as a support layer. In some nanoporous / mesoporous variants, the support layer may comprise materials or combinations thereof, such as activated carbon, quartz, zeolite, carbon nanotubes, organometallic frameworks, and covalent organic frameworks.

[0218] In a particular method for producing an adsorbent, providing the adsorbent support layer may include providing an oxide material suspension S111 in solution, which serves to form a solution having a suitable support layer material suspended therein. This can then be used to produce the adsorbent as described above. For example, the oxide material suspension may comprise aluminum oxide (Al2O3), silicon oxide (SiO2), cerium oxide (CeO2), zirconium oxide (ZrO2), iron oxide (FeO2), etc. x ) and / or alternative aluminosilicates.

[0219] In one variant, the solution is water, with the oxide material suspension provided in the water. Furthermore, in some variants, 1% wt to 30% wt of approximately 5% wt of oxide material may be provided in water as a suspension. For example, 4% to 6% (e.g., 5%) wt of oxide material may be provided in water as a suspension.

[0220] Block S120 includes reacting or grafting ionic functional groups onto the support layer as a trapping layer, the function of which is to construct ionic functional groups with adsorption sites on the material of the support layer. Various methods can be used to chemically or structurally react or graft the ionic functional group material onto the support layer. Preferably, according to the steps of block S120, the cation of the ion pair reacts or is grafted onto the support layer, and the anion of the ion pair associates with the cation.

[0221] Block S121 includes a process for passing deionized water through a cation exchange resin, which serves to prepare the cation exchange resin.

[0222] In one variant, deionized water is passed through a cation exchange resin (or more generally an ion exchange resin, i.e., IER)) until clear water is collected.

[0223] Block S122 includes performing ion exchange by adding a cation exchange resin to a solution, which can serve to purify impurities and remove pre-existing ions or materials present in oxides. In one variant, the cation exchange resin is added to the solution to perform ion exchange at least four or more times.

[0224] Box S123 includes mixing glycidyltrimethylammonium chloride (GTAC) into a suspension (i.e., an ion-exchanged oxide suspension) to attach or otherwise graft cations onto the surface of a support layer (e.g., an oxide material support layer). This may additionally or alternatively include mixed salts such as carbonates, oxalates, sulfates, sulfites, phosphates, phosphites, and borates (e.g., Na₂CO₃, K₂CO₃, Na₂C₂O₄, K₂C₂O₄, Na₃PO₄, K₃PO₄, Na₃PO₃, K₃PO₃, Na₂SO₄, K₂SO₄, Na₂SO₃, K₂SO₃, Na₃BO₃, K₃BO₃, etc.). In one variant, 6 mmol of glycidyltrimethylammonium chloride is mixed into the solution for every 1 gram of oxide suspension solution. In some variants, this may have a mass ratio of 1 to 10 GTAC to 1 oxide material. After mixing GTAC, the method may include stirring or otherwise mixing the solution.

[0225] Box S124 includes mixing a salt containing anion-pair anions into a solution, the purpose of which is to introduce anions associated with the support layer, for example, through bonding or grafting cations. The anions are preferably distributed on the surface of the nanoporous or mesoporous support layer, thereby providing a large surface area where CO2 capture can occur. Examples of such anionic materials may include sodium phosphate, sodium sulfite, sodium borate, or sodium carbonate and / or other salts, such as those disclosed herein. In other variations, the anionic material may include phosphates, sulfites, and / or borates. In some nanoporous support layer variations, such as when the support layer comprises activated carbon, quartz, zeolite, carbon nanotubes, organometallic framework materials, and covalent organic framework materials, the anionic material may be or include carbonate ions, sulfite ions, phosphate ions, and borate ions.

[0226] In the oxide nanoparticle variant of the support layer, anions can bond at various locations around the nanoparticles, resulting in a high surface area exposed to carbon dioxide adsorption sites.

[0227] This type of method may additionally include centrifuging the resulting solution after providing anions. Alternatively, other separation processes may be used.

[0228] 4. Direct air capture method

[0229] like Figure 9 As shown, a method for capturing a target gas using a humidity-oscillating adsorbent may include exposing the humidity-oscillating adsorbent to the target gas S220 and wetting the humidity-oscillating adsorbent S230. The method may further include providing a humidity-oscillating adsorbent S210, such as... Figure 10 As shown in the figure. The humidity oscillation adsorbent is preferably an adsorbent such as one of the variants described herein. Accordingly, the humidity oscillation adsorbent can be a material comprising: an adsorbent support layer of oxide material and / or nanoporous material, and a trapping layer comprising an ion-modified material having at least one adsorption site (e.g., a carbon dioxide adsorption site).

[0230] In some variants, the humidity-oscillating adsorbent can be reused. Accordingly, such as... Figure 11 As shown, a method for capturing a target gas using a humidity oscillating adsorbent may include: providing a humidity oscillating adsorbent S210; exposing the humidity oscillating adsorbent to the target gas S220; wetting the humidity oscillating adsorbent S230; drying the humidity oscillating adsorbent S240; and reusing the humidity oscillating adsorbent for subsequent exposure to the target gas S250.

[0231] The adsorbed target gas can preferably be extracted into a contained liquid form after wetting the loaded (or partially loaded) humidity-swirling adsorbent. The output of this wetting process can then be treated to separate or convert the target gas into a desired form for other uses (e.g., storage, use in other chemical processes). Accordingly, in some variations, the method may involve treating the output to wet the humidity-swirling adsorbent S260, such as... Figure 12 As shown in the image.

[0232] This method is particularly suitable for the capture and collection of target acidic gases such as carbon dioxide. For example, it can be used for direct air capture of CO2 for sequestration. Alternatively, the method can be used to capture other target gases from other gas streams from which the target gas may be desired, such as industrial gas streams.

[0233] Block S210 includes a humidity-wiggling adsorbent S210 for generating or otherwise using the humidity-wiggling adsorbent. The humidity-wiggling adsorbent is preferably a variant of the adsorbent described herein. The humidity-wiggling adsorbent can be similarly produced using any suitable method, including methods for producing adsorbents as described herein.

[0234] Block S220 includes exposing a humidity-oscillating adsorbent to a target gas, the function of which is to allow the gas to pass through the humidity-oscillating adsorbent so that a target gas, such as carbon dioxide, can be adsorbed into the adsorbent.

[0235] The target gas can be part of any other gas stream. In one variation of the method for direct air capture, the target gas can be part of natural air. In another variation, the target gas can be part of an industrial gas stream.

[0236] Exposure to a humidity-oscillating adsorbent can be achieved using any suitable method, such as forcing or otherwise directing the gas flow through the adsorbent. Active systems, such as fans, can be used. Alternatively, the humidity-oscillating adsorbent can be integrated into a capture device exposed to a moving gas flow. In another variation, the humidity-oscillating adsorbent can be passively exposed to ambient air or gas movement.

[0237] Humidity swings can expose the adsorbent so that it is fully or substantially loaded with the target gas before proceeding with extraction. However, the adsorbent can be loaded to any suitable level before proceeding. In one variation, the duration of exposure can be determined by some calculation or quantification based on time or gas volume to determine when the transition occurs.

[0238] In one variation, the method may include monitoring CO2 concentration to track, monitor, or otherwise quantify the amount of carbon dioxide adsorbed by the adsorbent. In one exemplary embodiment, an infrared gas analyzer may be used.

[0239] In one variant, the humidity-oscillating adsorbent can be exposed to a gas stream containing the target gas for a duration corresponding to the time window of target adsorption. For example... Figure 3 As shown, a time window ranging from 30 to 90 minutes can be used. In some variations, 10 to 30 minutes is sufficient to load or charge the adsorbent. In one exemplary embodiment, 1 gram of adsorbent can capture 0.8 mmol of CO2, although the adsorption ratio may vary depending on the implementation.

[0240] CO2 adsorption can be driven by a reaction such as the following, which will be driven under dry conditions.

[0241] dry: .

[0242] Box S230 includes a wetted humidity-wobbling adsorbent, which serves to trigger a humidity-wobbling reaction to release captured compounds (e.g., target gases, such as carbon dioxide) into the output solution. Water is preferably used to wet the humidity-wobbling adsorbent, but other aqueous solutions, water vapor, or other wetting solutions may also be used. Exposing the humidity-wobbling adsorbent to water or another suitable solution preferably induces ionic bonding of the target gas or its capture by anionic materials for release. Water is then passed through the adsorbent to wash away the selected target gas. The output of this process can be described or characterized as output water or an output solution.

[0243] The desorption of CO2 can be driven by a reaction such as the following, which will be driven under humid conditions.

[0244] Moist: .

[0245] The wetting duration of the adsorbent can be determined based on a predicted amount of target gas trapped in the adsorbent. For example... Figure 3 As shown, a wetting time window ranging from 30 to 90 minutes can be used. In one exemplary embodiment, 3 grams of water vapor can be used to trigger the desorption of 1 gram of CO2.

[0246] As mentioned, some variations of the method may include treating the humidity swing adsorbent for reuse, which may include drying the humidity swing adsorbent S240 and reusing the humidity swing adsorbent for subsequent exposure to the target gas S250.

[0247] Box S240 includes a dried humidity-wiggling adsorbent, the function of which is to reduce the moisture content of the humidity-wiggling adsorbent. This preferably occurs after the humidity-wiggling adsorbent has been wetted and all or a large portion (e.g., greater than 75%) of the captured target gas has been desorbed. The purpose of drying is to reset the adsorption sites of the adsorbent trapping layer.

[0248] Block S250 includes reusing the humidity-wiggling adsorbent for subsequent exposure to the target gas, with the aim of capturing more of the target gas using the humidity-wiggling adsorbent. Preferably, the adsorbent can be reused any suitable number of times by repeating S240 and S250 after loading and unloading the target gas from the adsorbent.

[0249] Block S260, which includes processing the output of a humidified oscillating adsorbent, serves to extract or otherwise prepare the target gas as the output of the wetting process (S230). In some variations, the output of S230 may be a water output containing the gaseous form of the target gas contained therein. In such variations, processing the output of the humidified oscillating adsorbent may include extracting the captured target gas from the output water using reduced pressure. A vacuum may be used to create a negative pressure difference, thereby extracting the gaseous target gas from the water. This separated gaseous target gas can then be further processed. For example, processing the output of the humidified oscillating adsorbent may additionally include compressing the captured target gas into a liquid form. The gaseous or liquid form of the target gas can be stored for sequestration. It can also be reused in various industrial applications.

[0250] 5. Systems for direct air capture

[0251] like Figure 5As shown, a system for adsorbing a target gas using a humidity-controlled oscillating adsorbent may include a humidity-controlled oscillating adsorbent 110, a gas exposure system 120, a wetting system 130, an adsorbent recovery system 140, and an optional water treatment system 150. In particular, this system can be used to capture carbon dioxide. This system can be used for direct air capture. Alternatively, this system can be used to capture carbon dioxide from other gas streams, such as industrial gas streams.

[0252] In one variant, the humidity-wiggling adsorbent 110 may be integrated within a chamber or body, wherein a gas exposure system 120, a humidification system 130, and an adsorbent recovery system 140 may be integrated to act on the humidity-wiggling adsorbent 110 within the chamber / body. In another variant, the humidity-wiggling adsorbent 110 may move or otherwise transport between one or more system components to facilitate the adsorption, desorption, and / or recovery of the humidity-wiggling adsorbent 110.

[0253] The function of the humidity oscillation adsorbent 110 is to enable the humidity oscillation reaction to adsorb carbon dioxide during loading and then desorb carbon dioxide gas as the humidity conditions change. The humidity oscillation adsorbent 100 can be any variation of the adsorbent described herein.

[0254] The gas exposure system 120 serves to facilitate the guidance of gas to and / or through the humidity-oscillating adsorbent 110. In one variation, the gas exposure system 120 guides air or gas through a passage within the humidity-oscillating adsorbent 110, thereby exposing the adsorbent to air or gas. Specifically, the air / gas may pass through a filter made of or containing the humidity-oscillating adsorbent 110. The gas exposure system 120 may include an air inlet and an outlet.

[0255] The system may include a sensing system to quantify and monitor the load on the humidity swing adsorbent 110. For example, an infrared gas analyzer may be used to track adsorbed carbon dioxide.

[0256] The function of the wetting system 130 is to expose the humidity swing adsorbent 110 to water or other suitable (e.g., aqueous) solution. The wetting system may be connected to a water outlet or a water vapor source. After the humidity swing adsorbent 110 has been partially or fully loaded, the wetting system 130 may be activated to change the humidity / moisture content to a state that triggers the desorption of carbon dioxide from the humidity swing adsorbent 110.

[0257] The wetting system 130 preferably includes a water output stream, which may be some output or discharge of liquid water or water vapor. Desorbed or released carbon dioxide gas is preferably mixed with the water output stream.

[0258] The adsorbent restoration system 140 functions to recreate drying conditions, thereby resetting the adsorption capacity of the humidity-oscillating adsorbent 110. The adsorbent restoration system 140 may include a heater, a fan, and / or other components to facilitate the drying of the humidity-oscillating adsorbent 110.

[0259] In some variations, the system may also include a water treatment system 150, which extracts or converts the state of carbon dioxide in the water output stream of the wetting system 130. The water treatment system may include a vacuum chamber and / or a pressurized chamber to extract carbon dioxide gas from the water and / or liquefy the carbon dioxide. The system may include other treatment systems to convert the carbon dioxide gas into other forms. Different forms of carbon dioxide product outputs can be tailored to different downstream utilization needs. For example, air containing approximately 420 ppm CO2 (e.g., 0.042%) can be converted by the system into suitable forms, such as a fluid containing approximately 1000 ppm (0.1%) CO2 for greenhouse fertilization, 5% to 20% for cement solidification and algae control, 15% to 30% for mineralization, and / or 99.9% for sustainable fuels.

[0260] As used herein, terms such as first, second, third, etc., are used to characterize and distinguish various elements, components, regions, layers, and / or portions. These elements, components, regions, layers, and / or portions should not be limited by these terms. Numerical terms are used to distinguish one element, component, region, layer, and / or portion from another. Unless the context clearly indicates otherwise, the use of such numerical terms does not imply any order or sequence. Such numerical references may be used interchangeably without departing from the teachings of the embodiments and variations herein.

[0261] As will be appreciated by those skilled in the art from the foregoing detailed description and from the accompanying drawings and claims, modifications and alterations may be made to embodiments of the invention without departing from the scope of the invention as defined in the following terms and claims.

[0262] This disclosure may also be described by the following numbered clauses:

[0263] 1. A composition of an adsorbent for adsorbing carbon dioxide, comprising:

[0264] Adsorbent carrier layer made of oxide material; and

[0265] The trapping layer comprises a set of neutral ion pairs having at least one cation and at least one anion, wherein the set of neutral ion pairs are spatially distributed on the support of the oxide material such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is a carbon dioxide adsorption site.

[0266] Optionally, the composition is an adsorbent composition according to any one of clauses 44 to 57.

[0267] 2. The composition according to Clause 1, wherein the oxide material is selected from the group consisting of: aluminum oxide (Al2O3), silicon oxide (SiO2), cerium oxide (CeO2), zirconium oxide (ZrO2), and iron oxide (FeO2). x ) and aluminosilicates.

[0268] 3. The composition according to Clause 1 or Clause 2, wherein the oxide material is a combination of materials selected from the group consisting of: aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), and iron oxide (FeO₂). x ), aluminosilicates and mesoporous ceramics.

[0269] 4. The composition according to any one of the preceding clauses, wherein the oxide material is a nanoporous oxide material, and optionally wherein the set of neutral ion pairs spatially distributed through the scaffold of the oxide material is contained in the pores of the oxide nanoporous material.

[0270] 5. The composition according to Clause 4, wherein the oxide material is a mesoporous oxide material.

[0271] 6. The composition according to Clause 4 or Clause 5, wherein neutral ion pairs in the pores of the oxide nanoporous material have anionic noncrystalline spacing to form a hydrated shell, and / or wherein fewer than 20 anions are present in each pore.

[0272] 7. The composition according to any one of the preceding clauses, wherein the oxide material is an oxide nanoparticle material, and wherein the set of neutral ion pairs spatially distributed on the support of the oxide material are spaced apart by each of the at least one cation spatially grafted onto the oxide nanoparticles of the oxide nanoparticle material.

[0273] 8. The composition according to Clause 4, wherein a plurality of neutral ion pairs are present on the nanoparticles grafted onto the oxide material.

[0274] 9. A composition of an adsorbent for adsorbing carbon dioxide, comprising:

[0275] Adsorbent carrier layer made of nanoporous material; and

[0276] The trapping layer comprises a set of neutral ion pairs of at least one cation and at least one anion, wherein the ion pairs are contained in the pores of the nanoporous material such that the anions of the set of neutral ion pairs are spaced apart within the pores to form a hydration shell, and wherein the hydration shell surrounding each anion of the set of neutral ion pairs is a carbon dioxide adsorption site.

[0277] Optionally, the composition is an adsorbent composition according to any one of clauses 44 to 57.

[0278] 10. The composition according to Clause 9, wherein the nanoporous material is a mesoporous material.

[0279] 11. The composition according to Clause 9 or Clause 10, wherein the nanoporous material is a material selected from the group consisting of: activated carbon, quartz, zeolite, carbon nanotubes, organometallic framework materials and covalent organic framework materials.

[0280] 12. The composition according to any one of clauses 9 to 11, wherein the nanoporous material is a nanoporous oxide material.

[0281] 13. The composition according to Clause 12, wherein the nanoporous oxide material is selected from the group consisting of: aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), and iron oxide (FeO₂). x ) and aluminosilicates.

[0282] 14. The composition according to Clause 12, wherein the nanoporous oxide material is a combination of materials selected from the group consisting of: aluminum oxide (Al₂O₃), silicon oxide (SiO₂), cerium oxide (CeO₂), zirconium oxide (ZrO₂), and iron oxide (FeO₂). x ) as well as aluminosilicates and mesoporous ceramics.

[0283] 15. The composition according to any one of the preceding clauses, wherein the hydration shell surrounding each anion of the set of neutral ion pairs is conditioned under a humidity condition.

[0284] 16. The composition according to any one of the preceding clauses, wherein, when under hydration shell conditions based on the number of water molecules, the presence of carbon dioxide drives a first reaction between carbon dioxide, the hydration shell, and anion to form at least bicarbonate ions within the hydration shell.

[0285] 17. The composition according to Clause 3, wherein the hydration shell condition based on the number of water molecules is when the number of water molecules is less than 50 per anion.

[0286] 18. The composition according to any one of the preceding clauses, wherein when the hydrated shell decomposes under conditions based on the number of water molecules, the hydrated shell decomposes by a second reaction that releases CO2 from bicarbonate ions into the aqueous phase.

[0287] 19. The composition according to Clause 18, wherein the condition for the decomposition of the hydrated shell based on the number of water molecules is when the number of water molecules is greater than 50 per anion.

[0288] 20. The composition according to any one of the preceding clauses, wherein the at least one anion is borate ion (BO3). 3- The first reaction is characterized by:

[0289] ,

[0290] And the second reaction is characterized by:

[0291] .

[0292] 21. The composition according to any one of the preceding clauses, wherein the at least one anion is a carbonate ion (CO3-). 2- The first reaction is characterized by:

[0293] ,

[0294] And the second reaction is characterized by:

[0295] .

[0296] 22. The composition according to any one of the preceding clauses, wherein the at least one anion is oxalate ion (C2O4). 2- The first reaction is characterized by:

[0297] ,

[0298] And the second reaction is characterized by:

[0299] .

[0300] 23. The composition according to any one of the preceding clauses, wherein the at least one anion is sulfite ion (SO32-). 2- The first reaction is characterized by:

[0301] ,

[0302] And the second reaction is characterized by:

[0303] .

[0304] 24. The composition according to any one of the preceding clauses, wherein the at least one anion is a phosphite ion (PO3). 3- The first reaction is characterized by:

[0305] ,

[0306] And the second reaction is characterized by:

[0307] .

[0308] 25. The composition according to any one of the preceding clauses, wherein the at least one anion is a phosphate ion (PO4). 3- The first reaction is characterized by:

[0309] ,

[0310] And the second reaction is characterized by:

[0311] .

[0312] 26. The composition according to any one of the preceding clauses, wherein the hydrated shell has 1-3 layers.

[0313] 27. The composition according to any one of the preceding clauses, wherein, in a dry state, the adsorbent adsorbs CO2 by converting CO2 into carbonate in the presence of a gas stream, and in a humid state, the adsorbent releases CO2 and the trapping layer reverts to the set of neutral ion pairs having a hydrated shell when returned to a dry state.

[0314] 28. The composition according to any one of the preceding clauses, wherein the at least one cation is selected from the group consisting of positively charged ions: Na + K + and glycidyltrimethylammonium (GTA) + ), and / or said at least one anion is selected from the group of negatively charged ions consisting of: carbonate (CO3-) 2- ), oxalate (C2O4) 2- ), phosphate (PO4) 3- ), phosphate (PO3) 2- ), sulfite (SO3) 2- ), sulfate (SO 4- ), borate (BO3) 3- ) and silicate (SiO4)4- ).

[0315] 29. The composition according to Clause 28, wherein the set of neutral ion pairs is a combination of a neutral ion pair and different anions selected from the group of negatively charged ions.

[0316] 30. A method for producing a carbon dioxide adsorbent, comprising:

[0317] Provides an adsorbent carrier layer made of oxide materials;

[0318] The ion functional group reacts with the carrier layer, which serves as the trapping layer, wherein the ion functional group has at least one carbon dioxide adsorption site.

[0319] Optionally, the method described herein includes the method according to any one of clauses 58 to 68.

[0320] 31. The method according to clause 30, wherein providing the adsorbent support layer comprises an oxide material suspension provided in solution; and wherein reacting the ionic functional groups with the support layer serving as the trapping layer comprises:

[0321] Optionally, deionized water can be passed through the cation exchange resin to clean the resin.

[0322] Ion exchange is performed by adding the cation exchange resin to a solution of suspended oxide material.

[0323] Glycidyltrimethylammonium chloride (GTAC) was mixed into the solution of the suspended oxide material, and

[0324] A salt containing anions (such as polyvalent anions) is mixed into a solution of the suspended oxide material mixed with GTAC.

[0325] 32. The method according to Clause 31, wherein the oxide material suspension is in water, for example, comprising about 5% wt of oxide material based on the weight of the solution.

[0326] 33. The method according to Clause 31 or Clause 32, wherein performing the ion exchange comprises adding the cation exchange resin to the oxide material suspension at least four times.

[0327] 34. The method according to any one of clauses 31 to 33, wherein for every 1 gram of oxide suspension, about 6 mmol of glycidyltrimethylammonium chloride is mixed into the solution.

[0328] 35. The method according to any one of clauses 30 to 34, wherein the oxide material is selected from the group consisting of: aluminum oxide (Al2O3), silicon oxide (SiO2), cerium oxide (CeO2), zirconium oxide (ZrO2), iron oxide (FeO2). x ) and aluminosilicates.

[0329] 36. The method according to any one of clauses 30 to 34, wherein the oxide material is a combination of materials selected from the group consisting of: aluminum oxide (Al2O3), silicon oxide (SiO2), cerium oxide (CeO2), zirconium oxide (ZrO2), and iron oxide (FeO2). x ) as well as aluminosilicates and mesoporous ceramics.

[0330] 37. The method according to any one of clauses 30 to 36, wherein the anion is selected from the group consisting of: carbonate, oxalate, phosphate, phosphite, sulfate, sulfite, silicate and borate.

[0331] 38. The method according to any one of clauses 30 to 27, wherein the anion is provided in the form of a salt, such as a salt selected from the group consisting of sodium and / or potassium salts of phosphates, phosphites, sulfites, sulfates, borates, silicates, oxalates and carbonates.

[0332] 39. A method for capturing carbon dioxide, comprising:

[0333] A humidity oscillating adsorbent is provided, wherein the humidity oscillating adsorbent comprises the following materials:

[0334] An adsorbent carrier layer made of materials selected from the group consisting of oxide nanoparticles and nanoporous materials, and

[0335] The trapping layer comprises a set of neutral ion pairs having at least one cation and at least one anion, wherein the set of neutral ion pairs are spatially distributed by a support of the oxide material such that the anions of each neutral ion pair are spaced apart to form a hydrated shell around each anion, wherein the hydrated shell around the anion is a carbon dioxide adsorption site.

[0336] Expose the humidity-oscillating adsorbent to the target gas; and

[0337] Wetting the humidity-oscillating adsorbent;

[0338] Optionally, the method described herein includes the method according to any one of clauses 69 to 79.

[0339] 40. The method according to Clause 39, wherein wetting the humidity-oscillating adsorbent comprises collecting output water containing the released target gas.

[0340] 41. The method according to Clause 40, further comprising treating the output water to capture the target gas.

[0341] 42. The method according to any one of clauses 39 to 41, wherein the target gas is carbon dioxide.

[0342] 43. The method according to any one of clauses 39 to 42, further comprising drying the humidity oscillating adsorbent and reusing the humidity oscillating adsorbent for subsequent exposure to the target gas.

[0343] 44. An adsorbent composition for adsorbing a target gas from a gas stream, wherein the adsorbent composition comprises a covalent network solid oxide substrate material functionalized with ion-linking groups, wherein each ion-linking group comprises:

[0344] polyvalent anions, and

[0345] Polyatomic cations selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfite;

[0346] The polyatomic cations are covalently bonded to oxygen atoms on the surface of the substrate material;

[0347] Optionally, the adsorbent composition is the composition according to any one of clauses 1 to 29.

[0348] 45. An adsorbent precursor for an adsorbent composition for adsorbing a target gas from a gas stream, wherein the adsorbent precursor comprises a covalent network solid oxide substrate material functionalized with an ion-linking precursor, wherein each ion-linking precursor comprises:

[0349] Monovalent anions, and

[0350] Polyatomic cations selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfite;

[0351] The polyatomic cations are covalently bonded to oxygen atoms on the surface of the substrate material;

[0352] Optionally, the adsorbent precursor is a precursor of the composition according to any one of clauses 1 to 29.

[0353] 46. ​​The adsorbent composition according to Clause 44 or the adsorbent precursor according to Clause 45, wherein the target gas is CO2.

[0354] 47. The adsorbent composition or adsorbent precursor according to any one of clauses 44 to 46, wherein the polyatomic cation has the formula R (R'). x A + ,in:

[0355] R is a hydrocarbon-containing group covalently bonded to an oxygen atom on the surface of the substrate material, or R is a covalent bond to an oxygen atom on the surface of the substrate material; and,

[0356] Each R' is independently a hydrocarbon group or H;

[0357] And among them:

[0358] x is 3, and A is N, P, As, Sb, or Bi; or,

[0359] x is 2, and A is S;

[0360] Choose one of them:

[0361] R is an optionally substituted C1 to C8 hydrocarbon group; and / or,

[0362] R' is a C1 to C6 alkyl group (such as methyl, ethyl, propyl, or butyl), or R' is an aryl group (such as phenyl).

[0363] 48. The adsorbent composition or adsorbent precursor according to any one of clauses 44 to 47, wherein:

[0364] The polyatomic cations are spaced apart on the surface (e.g., in the pores) of the covalent network solid oxide material at an average spacing not exceeding about 50 Å, such as not exceeding about 20 Å, for example not exceeding about 10 Å; and / or

[0365] The polyatomic cations are spaced apart at a distance of about 4 Å to about 50 Å, such as about 6 Å to 20 Å, for example about 8 Å to 10 Å.

[0366] 49. An adsorbent composition or adsorbent precursor according to any one of clauses 44 to 48, wherein the polyatomic cation is ammonium, phosphonium, or sulfonium, optionally wherein the polyatomic cation is an ammonium cation, such as a quaternary ammonium cation, for example a cation containing trimethylammonium.

[0367] 50. The adsorbent composition according to any one of clauses 44 to 49, wherein the polyvalent anion comprises or consists of oxygen and elements from or composed of ... 3- CO3 2 C2O4 2- SiO44- PO3 3- PO4 3- SO3 2- and SO4 2- .

[0368] 51. The adsorbent composition according to any one of clauses 44 to 50, wherein the polyvalent anion comprises or consists of hydrogen, oxygen, and elements from or composed of ... 2- HCO3 - HC2O4 - HSiO4 3- HPO3 2- HPO4 2- HSO3 - and HSO4 - ;

[0369] The adsorbent composition further comprises the formula (TG)OH - The anion, wherein TG is the target gas, and wherein (TG)OH - The polyvalent anion exists in a molar ratio of approximately 1:1;

[0370] Optionally, the target gas is CO2, and (TG)OH - HCO 3- .

[0371] 52. The adsorbent composition according to any one of clauses 44 to 51, comprising the polyvalent anion in an amount of about 0.2 mmol to about 3 mmol, such as about 0.3 mmol to about 2.5 mmol, for example about 0.5 mmol to about 2 mmol per gram of covalent network solid oxide material.

[0372] 53. An adsorbent composition or adsorbent precursor according to any one of clauses 44 to 52, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with a carbon atom of a linker precursor reactant susceptible to nucleophilic attack, thereby forming a CO covalent bond, for example, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with an epoxy group of a linker precursor reactant, thereby forming a CO covalent bond.

[0373] 54. The adsorbent composition or adsorbent precursor according to Clause 53, wherein the linker precursor reactant comprises a cation selected from N-[3-(trimethoxysilyl)propyl]-N,N,N-trimethylammonium, N-(trimethoxysilylpropyl)-N,N,N-trimethylphosphonium, and glycidyltrimethylammonium, for example, wherein the linker precursor reactant comprises glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each oxygen on the surface of the substrate material with the epoxy group of the glycidyltrimethylammonium cation to form a CO covalent bond.

[0374] 55. The adsorbent composition or adsorbent precursor according to any one of clauses 44 to 54, wherein the covalent network solid oxide substrate material comprises one or more of silica, alumina, cerium dioxide, zirconium oxide, iron oxide and aluminosilicate.

[0375] 56. The adsorbent composition according to any one of clauses 44 to 55, comprising water, wherein the water is present in a water:polyvalent anion molar ratio of 1:10 to 40:1, such as 1:1 to 1:20.

[0376] 57. The adsorbent composition according to any one of clauses 44 to 56, comprising water, wherein the water is present in a water:polyvalent anion molar ratio greater than 40:1, such as at least 50:1.

[0377] 58. A method for preparing an adsorbent composition for adsorbing a target gas from a gas stream, wherein the method comprises:

[0378] An adsorbent precursor is formed by contacting a covalent network solid oxide substrate material with a linker precursor reactant, wherein the linker precursor reactant comprises anions and polyatomic cations, wherein the polyatomic cations are selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfonium, and wherein the contact is performed under conditions that the covalent bonds between oxygen atoms on the surface of the substrate material and the polyatomic cations are effective.

[0379] The adsorbent precursor is contacted with an ionic compound comprising a metal from Group 1 or Group 2 of the periodic table and a polyvalent anion, wherein the contact is performed under conditions effective for inducing ion exchange, thereby exchanging the polyvalent anion into a monovalent anion; and,

[0380] Salts comprising the metals from Group 1 or Group 2 of the periodic table and the monovalent anions;

[0381] Optionally, the method described herein includes the method according to any one of clauses 30 to 38.

[0382] 59. The method according to Clause 58, comprising forming a suspension of the covalent network solid oxide material in an aqueous solution (such as water), adding the linker precursor reactant to the suspension to form an intermediate mixture, and adding the ionic compound to the mixture of the suspension and the linker precursor reactant to form a product mixture.

[0383] 60. The method according to Clause 58 or Clause 59, wherein the step of removing the salt comprises centrifuging the product mixture, optionally thereby separating the byproduct solution containing water and the salt from the adsorbent composition.

[0384] 61. A method for preparing an adsorbent precursor for an adsorbent composition for adsorbing a target gas from a gas stream, wherein the method comprises contacting a covalent network solid oxide substrate material with a linker precursor reactant, wherein the linker precursor reactant comprises anions and polyatomic cations, wherein the polyatomic cations are selected from ammonium, phosphonium, arsenic, antimony, bismuth, and sulfonium, and wherein the contact is performed under conditions that the covalent bonds between oxygen atoms on the surface forming the substrate material and the polyatomic cations are effective.

[0385] 62. The method according to Clause 61, comprising forming a suspension of the covalent network solid oxide material in an aqueous solution (such as water) and adding the linker precursor reactant to the suspension to form a mixture comprising the precursor.

[0386] 63. The method according to any one of clauses 58 to 62, comprising subjecting the covalent network solid oxide material to ion exchange prior to contacting the covalent network solid oxide material with the linker precursor reactant, optionally wherein the covalent network solid oxide material is subjecting to ion exchange by suspending the covalent network solid oxide material in an aqueous solution (such as water) and contacting the suspension with an ion exchange resin, optionally wherein the ion exchange resin is first cleaned by contacting deionized water.

[0387] 64. The method according to any one of clauses 58 to 63, wherein the target gas is CO2.

[0388] 65. The method according to any one of Clauses 58 to 64, wherein any one of the adsorbent composition, adsorbent precursor, polyatomic cation, ionic compound (if present), and / or salt (if present) is as defined in any one of Clauses 44 to 57.

[0389] 66. The method according to any one of clauses 58 to 65, comprising:

[0390] The ion-linking group portion is added in an amount providing a weight ratio of about 1:5 to about 1:0.04, such as about 1:4 to about 1:0.06, to the covalent network oxide solid material, where the ratio is, for example, the weight (in grams) of each material; and / or

[0391] The ion-linking group portion is added in an amount of about 80 mmol to 160 mmol, for example about 100 mmol to about 140 mmol, per gram of the covalent network solid oxide substrate material.

[0392] 67. The method according to any one of clauses 58 to 66, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with a carbon atom of a linker precursor reactant susceptible to nucleophilic attack, thereby forming a CO covalent bond, for example, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with an epoxy group of a linker precursor reactant, thereby forming a CO covalent bond.

[0393] 68. The method according to any one of claims 58 to 67, wherein the linker precursor reactant comprises a cation selected from N-[3-(trimethoxysilyl)propyl]-N,N,N-trimethylammonium, N-(trimethoxysilylpropyl)-N,N,N-trimethylphosphonium, and glycidyltrimethylammonium, for example, wherein the linker precursor reactant comprises glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with the epoxy group of the glycidyltrimethylammonium cation to form a CO covalent bond.

[0394] 69. A method for removing a target gas from a gas stream having a first target gas concentration, wherein the method includes contacting the gas stream with an adsorbent composition;

[0395] The adsorbent composition comprises a covalent network solid oxide substrate material functionalized with ion-linking groups, wherein each ion-linking group comprises:

[0396] polyvalent anions, and

[0397] Polyatomic cations selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfite;

[0398] The polyatomic cations are covalently bonded to oxygen atoms on the surface of the substrate material;

[0399] The target gas is adsorbed by the adsorbent composition, thereby forming an adsorbent composition enriched with the target gas and a product gas stream having a second target gas concentration.

[0400] Furthermore, the concentration of the second target gas is lower than the concentration of the first target gas.

[0401] 70. The method according to Clause 69, wherein the target gas is CO2.

[0402] 71. The method according to Clause 69 or Clause 70, wherein the adsorbent composition is as defined in Clause 44 or any of Clauses 46 to 56.

[0403] 72. A method for removing a target gas from an adsorbent composition enriched with a target gas, wherein the method comprises contacting the adsorbent composition enriched with the target gas with a gas stream and water, wherein the gas stream has a first target gas concentration;

[0404] The adsorbent composition for enriching the target gas comprises a covalent network solid oxide substrate material functionalized with ion-linking groups, wherein each ion-linking group comprises:

[0405] polyvalent anions, and

[0406] Polyatomic cations selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfite;

[0407] The polyatomic cations are covalently bonded to oxygen atoms on the surface of the substrate material;

[0408] The target gas is released from the adsorbent composition enriched with the target gas, thereby forming a wetted adsorbent composition and a product stream (such as a product gas stream) having a second target gas concentration, wherein the second target gas concentration is higher than the first target gas concentration.

[0409] 73. The method according to Clause 72, wherein the target gas is CO2.

[0410] 74. The method according to Clause 72 or Clause 73, wherein the adsorbent composition is as defined in any one of Clauses 44, 46 to 55 or Clause 57.

[0411] 75. The method according to any one of clauses 72 to 74, further comprising drying the moistened adsorbent composition to form the adsorbent composition.

[0412] 76. The method according to Clause 75, wherein the adsorbent composition comprises water, wherein the water is present in a water:polyvalent anion molar ratio of 1:10 to 40:1, such as 1:1 to 1:20.

[0413] 77. A method for processing a gas stream, comprising performing the method according to any one of clauses 69 to 71, and subsequently performing the method according to any one of clauses 72 to 74; optionally, said method includes the method according to any one of clauses 39 to 43.

[0414] 78. The method according to Clause 77, comprising performing the method according to Clause 75 or 76 after performing the steps of the method according to any one of Clauses 72 to 74, and optionally reusing the adsorbent composition thus formed to repeat the method according to any one of Clauses 69 to 71.

[0415] 79. The method according to Clause 78, comprising separating the target gas from the product stream.

[0416] 80. A porous membrane for separating a target gas from a gas stream, wherein the porous membrane comprises the adsorbent composition according to claim 1.

[0417] 81. The porous membrane according to clause 80, wherein the target gas is CO2.

[0418] 82. A porous membrane according to Clause 80 or Clause 81, comprising or consisting of the adsorbent composition.

[0419] 83. The porous membrane according to clause 80 or clause 81, wherein the adsorbent composition is loaded on a membrane material, such as a polymer membrane material.

[0420] 84. An apparatus for separating a target gas from a gas stream, wherein the apparatus comprises an adsorbent composition according to any one of Clauses 44 or 46 to 57, wherein the adsorbent composition is arranged to contact the gas stream.

[0421] 85. The apparatus according to Clause 84, wherein the target gas is CO2.

[0422] 86. The device according to Clause 84 or Clause 85, comprising a porous membrane according to any one of Clauses 80 to 83.

Claims

1. An adsorbent composition for adsorbing a target gas from a gas stream, wherein the adsorbent composition comprises a covalent network solid oxide substrate material functionalized with ion-linking groups, wherein each ion-linking group comprises: polyvalent anions, and Polyatomic cations selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfite; The polyatomic cation is covalently bonded to oxygen atoms on the surface of the substrate material.

2. The adsorbent composition according to claim 1, wherein the target gas is CO2.

3. The adsorbent composition according to claim 1, wherein the polyatomic cation has the formula R(R'). x A + ,in: R is a hydrocarbon-containing group covalently bonded to an oxygen atom on the surface of the substrate material, or R is a covalent bond to an oxygen atom on the surface of the substrate material; and, Each R' is independently a hydrocarbon group or H; And among them: x is 3, and A is N, P, As, Sb, or Bi; or, x is 2, and A is S.

4. The adsorbent composition according to claim 3, wherein: R is an optionally substituted C1 to C8 hydrocarbon group; and / or, R' is a C1 to C6 alkyl group (such as methyl, ethyl, propyl, or butyl), or R' is an aryl group (such as phenyl).

5. The adsorbent composition according to claim 1, wherein the polyatomic cation is ammonium, phosphonium, or sulfonium, optionally wherein the polyatomic cation is an ammonium cation, such as a quaternary ammonium cation, for example a cation containing trimethylammonium.

6. The adsorbent composition according to claim 1, wherein: The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing not exceeding about 50 Å, such as not exceeding about 20 Å, for example not exceeding about 10 Å; and / or The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing of about 4 Å to about 50 Å, such as about 6 Å to 20 Å, for example about 8 Å to 10 Å.

7. The adsorbent composition according to claim 1, wherein the polyvalent anion comprises oxygen and elements from Group 15 or Group 16 of the periodic table, for example, wherein the polyvalent anion is selected from: BO3 3- CO3 2 C2O4 2- SiO4 4- PO3 3- PO4 3- SO3 2- and SO4 2- .

8. The adsorbent composition according to claim 1, wherein the polyvalent anion comprises hydrogen, oxygen, and elements from Group 15 or Group 16 of the periodic table, for example, wherein the polyvalent anion is selected from HBO3. 2- HCO3 - HC2O4 - HSiO4 3- HPO3 2- HPO4 2- HSO3 - and HSO4 - ; The adsorbent composition further comprises the formula (TG)OH - The anion, wherein TG is the target gas, and wherein (TG)OH - The polyvalent anion exists in a molar ratio of approximately 1:1; Optionally, the target gas is CO2, and (TG)OH - HCO 3- .

9. The adsorbent composition according to claim 1, comprising the polyvalent anion in an amount of about 0.2 mmol to about 3 mmol, such as about 0.3 mmol to about 2.5 mmol, for example about 0.5 mmol to about 2 mmol per gram of covalent network solid oxide material.

10. The adsorbent composition of claim 1, wherein the substrate material is functionalized by reacting each oxygen atom on the surface of the substrate material with a carbon atom of a nucleophilically attacked linker precursor reactant to form a CO covalent bond.

11. The adsorbent composition of claim 10, wherein the linker precursor reactant comprises glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with the epoxy group of the glycidyltrimethylammonium cation to form the CO covalent bond.

12. The adsorbent composition according to claim 1, wherein the covalent network solid oxide substrate material comprises one or more of silicon dioxide, aluminum oxide, cerium dioxide, zirconium oxide, iron oxide, and aluminosilicate.

13. The adsorbent composition according to claim 1, comprising water, wherein the water is present in a water:polyvalent anion molar ratio of 1:10 to 40:1, such as 1:1 to 1:

20.

14. The adsorbent composition of claim 1, comprising water, wherein the water is present in a water:polyvalent anion molar ratio greater than 40:1, such as at least 50:

1.

15. An adsorbent precursor for an adsorbent composition for adsorbing a target gas from a gas stream, wherein the adsorbent precursor comprises a covalent network solid oxide substrate material functionalized with an ion-linking precursor, wherein each ion-linking precursor comprises: Monovalent anions, and Polyatomic cations selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfite; The polyatomic cation is covalently bonded to oxygen atoms on the surface of the substrate material.

16. The adsorbent precursor according to claim 15, wherein the target gas is CO2.

17. The adsorbent precursor according to claim 15, wherein the monovalent anion is a halide, such as a chloride.

18. The adsorbent precursor according to claim 15, wherein the polyatomic cation has the formula R (R'). x A + ,in: R is a hydrocarbon-containing group covalently bonded to an oxygen atom on the surface of the substrate material, or R is a covalent bond to an oxygen atom on the surface of the substrate material; and, Each R' is independently a hydrocarbon group or H; And among them: x is 3, and A is N, P, As, Sb, or Bi; or, x is 2, and A is S.

19. The adsorbent precursor according to claim 18, wherein: R is an optionally substituted C1 to C8 hydrocarbon group; and / or, R' is a C1 to C6 alkyl group (such as methyl, ethyl, propyl, or butyl), or R' is an aryl group (such as phenyl).

20. The adsorbent precursor according to claim 15, wherein: The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing not exceeding about 50 Å, such as not exceeding about 20 Å, for example not exceeding about 10 Å; and / or The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing of about 4 Å to about 50 Å, such as about 6 Å to 20 Å, for example about 8 Å to 10 Å.

21. The adsorbent precursor of claim 15, wherein the polyatomic cation is ammonium, phosphonium, or sulfonium, optionally wherein the polyatomic cation is an ammonium cation, such as a quaternary ammonium cation, for example a cation containing trimethylammonium.

22. The adsorbent precursor of claim 14, comprising about 2 to 10 mmol of the ion-linking precursor per gram of the covalent network solid oxide substrate material, for example, about 5 to 7 mmol per gram.

23. The adsorbent precursor of claim 15, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with a carbon atom of a nucleophilically attacked linker precursor reactant to form a CO covalent bond.

24. The adsorbent precursor of claim 23, wherein the linker precursor reactant comprises glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with the epoxy group of the glycidyltrimethylammonium cation to form the CO covalent bond.

25. The adsorbent precursor according to claim 15, wherein the covalent network solid oxide substrate material comprises one or more of silicon dioxide, aluminum oxide, cerium dioxide, zirconium oxide, iron oxide, and aluminosilicate.

26. A method for preparing an adsorbent composition for adsorbing a target gas from a gas stream, wherein the method comprises: An adsorbent precursor is formed by contacting a covalent network solid oxide substrate material with a linker precursor reactant, wherein the linker precursor reactant comprises anions and polyatomic cations, wherein the polyatomic cations are selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfonium, and wherein the contact is performed under conditions that the covalent bonds between oxygen atoms on the surface of the substrate material and the polyatomic cations are effective. The adsorbent precursor is contacted with an ionic compound comprising a metal from Group 1 or Group 2 of the periodic table and a polyvalent anion, wherein the contact is performed under conditions effective for inducing ion exchange, thereby exchanging the polyvalent anion into a monovalent anion; and, Salts containing the metals from Group 1 or Group 2 of the periodic table and the monovalent anions are excluded.

27. The method of claim 26, further comprising forming a suspension of the covalent network solid oxide material in an aqueous solution (such as water), adding the linker precursor reactant to the suspension to form an intermediate mixture, and adding the ionic compound to the mixture of the suspension and the linker precursor reactant to form a product mixture.

28. The method of claim 27, wherein the step of removing the salt comprises centrifuging the product mixture, optionally thereby separating a byproduct solution comprising water and the salt from the adsorbent composition.

29. The method of claim 26, further comprising subjecting the covalent network solid oxide material to ion exchange prior to contacting the covalent network solid oxide material with the linker precursor reactant, optionally wherein the covalent network solid oxide material is subjecting to ion exchange by suspending the covalent network solid oxide material in an aqueous solution (such as water) and contacting the suspension with an ion exchange resin, optionally wherein the ion exchange resin is first cleaned by contacting deionized water.

30. The method of claim 26, wherein the target gas is CO2.

31. The method of claim 26, wherein the polyatomic cation has the formula R(R'). x A + ,in: R is a hydrocarbon-containing group covalently bonded to an oxygen atom on the surface of the substrate material, or R is a covalent bond to an oxygen atom on the surface of the substrate material; and, Each R' is independently a hydrocarbon group or H; And among them: x is 3, and A is N, P, As, Sb, or Bi; or, x is 2, and A is S.

32. The method according to claim 31, wherein: R is an optionally substituted C1 to C8 hydrocarbon group; and / or, R' is a C1 to C6 alkyl group (such as methyl, ethyl, propyl, or butyl), or R' is an aryl group (such as phenyl).

33. The method according to claim 26, wherein: The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing not exceeding about 50 Å, such as not exceeding about 20 Å, for example not exceeding about 10 Å; and / or The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing of about 4 Å to about 50 Å, such as about 6 Å to 20 Å, for example about 8 Å to 10 Å.

34. The method of claim 26, wherein the polyatomic cation is ammonium, phosphonium, or sulfonium, optionally wherein the polyatomic cation is an ammonium cation, such as a quaternary ammonium cation, for example a cation containing trimethylammonium.

35. The method of claim 26, wherein the polyvalent anion comprises oxygen and elements from Group 15 or Group 16 of the periodic table, for example, wherein the polyvalent anion is selected from: BO3 3- CO3 2 C2O4 2- SiO4 4- PO3 3- PO4 3- SO3 2- and SO4 2- .

36. The method of claim 26, wherein the polyvalent anion comprises hydrogen, oxygen, and elements from Group 15 or Group 16 of the periodic table, for example, wherein the polyvalent anion is selected from HBO3. 2- HCO3 - HC2O4 - HSiO4 3- HPO3 2- HPO4 2- HSO3 - and HSO4 - ; The adsorbent composition further comprises the formula (TG)OH - The anion, wherein TG is the target gas, and wherein (TG)OH - The polyvalent anion exists in a molar ratio of approximately 1:1; Optionally, the target gas is CO2, and (TG)OH - HCO 3- .

37. The method of claim 26, further comprising: The ion-linking group portion is added in an amount providing a weight ratio of about 1:5 to about 1:0.04, such as about 1:4 to about 1:0.06, to the covalent network oxide solid material; and / or The ion-linking group is added in an amount of about 80 mmol to 160 mmol, for example about 100 mmol to about 140 mmol per gram of the covalent network solid oxide substrate material.

38. The method of claim 26, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with a carbon atom of a nucleophilically attacked linker precursor reactant to form a CO covalent bond.

39. The method of claim 38, wherein the linker precursor reactant comprises glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with the epoxy group of the glycidyltrimethylammonium cation to form the CO covalent bond.

40. The method of claim 26, wherein the covalent network solid oxide substrate material comprises one or more of silicon dioxide, aluminum oxide, cerium dioxide, zirconium oxide, iron oxide, and aluminosilicate.

41. The method of claim 26, wherein the adsorbent composition comprises water, wherein the water is present in a water:polyvalent anion molar ratio of 1:10 to 40:1, such as 1:1 to 1:

20.

42. The method of claim 26, wherein the adsorbent composition comprises water, wherein the water is present in a water:polyvalent anion molar ratio greater than 40:1, such as at least 50:

1.

43. A method for preparing an adsorbent precursor for an adsorbent composition for adsorbing a target gas from a gas stream, wherein the method comprises contacting a covalent network solid oxide substrate material with a linker precursor reactant, wherein the linker precursor reactant comprises anions and polyatomic cations, wherein the polyatomic cations are selected from ammonium, phosphonium, arsenic, antimony, bismuth, and sulfonium, and wherein the contact is performed under conditions that the covalent bonds between oxygen atoms on the surface forming the substrate material and the polyatomic cations are effective.

44. The method of claim 43, further comprising forming a suspension of the covalent network solid oxide material in an aqueous solution (such as water), and adding the linker precursor reactant to the suspension to form a mixture comprising the precursor.

45. The method of claim 43, further comprising subjecting the covalent network solid oxide material to ion exchange prior to contacting the covalent network solid oxide material with the linker precursor reactant, optionally wherein the covalent network solid oxide material is subjecting to ion exchange by suspending the covalent network solid oxide material in an aqueous solution (such as water) and contacting the suspension with an ion exchange resin, optionally wherein the ion exchange resin is first cleaned by contacting deionized water.

46. ​​The method of claim 43, wherein the target gas is CO2.

47. The method of claim 43, wherein the polyatomic cation has the formula R(R'). x A + ,in: R is a hydrocarbon-containing group covalently bonded to an oxygen atom on the surface of the substrate material, or R is a covalent bond to an oxygen atom on the surface of the substrate material; and, Each R' is independently a hydrocarbon group or H; And among them: x is 3, and A is N, P, As, Sb, or Bi; or, x is 2, and A is S.

48. The method of claim 47, wherein: R is an optionally substituted C1 to C8 hydrocarbon group; and / or, R' is a C1 to C6 alkyl group (such as methyl, ethyl, propyl, or butyl), or R' is an aryl group (such as phenyl).

49. The method of claim 43, wherein the polyatomic cation is ammonium, phosphonium, or sulfonium, optionally wherein the polyatomic cation is an ammonium cation, such as a quaternary ammonium cation, for example a cation containing trimethylammonium.

50. The method of claim 43, further comprising: The ion-linking group portion is added in an amount providing a weight ratio of about 1:5 to about 1:0.04, such as about 1:4 to about 1:0.06, to the covalent network oxide solid material; and / or The ion-linking group is added in an amount of about 80 mmol to 160 mmol, for example about 100 mmol to about 140 mmol per gram of the covalent network solid oxide substrate material.

51. The method of claim 43, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with a carbon atom of a nucleophilically attacked linker precursor reactant to form a CO covalent bond.

52. The method of claim 51, wherein the linker precursor reactant comprises glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with the epoxy group of the glycidyltrimethylammonium cation to form the CO covalent bond.

53. The method of claim 43, wherein the covalent network solid oxide substrate material comprises one or more of silicon dioxide, aluminum oxide, cerium dioxide, zirconium oxide, iron oxide, and aluminosilicate.

54. A method for removing a target gas from a gas stream having a first target gas concentration, wherein the method includes contacting the gas stream with an adsorbent composition; The adsorbent composition comprises a covalent network solid oxide substrate material functionalized with ion-linking groups, wherein each ion-linking group comprises: polyvalent anions, and Polyatomic cations selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfite; The polyatomic cations are covalently bonded to oxygen atoms on the surface of the substrate material; The target gas is adsorbed by the adsorbent composition, thereby forming an adsorbent composition enriched with the target gas and a product gas stream having a second target gas concentration. Furthermore, the concentration of the second target gas is lower than the concentration of the first target gas.

55. The method of claim 54, wherein the target gas is CO2.

56. The method of claim 54, wherein the polyatomic cation has the formula R(R'). x A + ,in: R is a hydrocarbon-containing group covalently bonded to an oxygen atom on the surface of the substrate material, or R is a covalent bond to an oxygen atom on the surface of the substrate material; and, Each R' is independently a hydrocarbon group or H; And among them: x is 3, and A is N, P, As, Sb, or Bi; or, x is 2, and A is S.

57. The method according to claim 56, wherein: R is an optionally substituted C1 to C8 hydrocarbon group; and / or, R' is a C1 to C6 alkyl group (such as methyl, ethyl, propyl, or butyl), or R' is an aryl group (such as phenyl).

58. The method of claim 54, wherein the polyatomic cation is ammonium, phosphonium, or sulfonium.

59. The method of claim 54, wherein the polyatomic cation is an ammonium cation, such as a quaternary ammonium cation, for example including cations containing trimethylammonium.

60. The method of claim 54, wherein: The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing not exceeding about 50 Å, such as not exceeding about 20 Å, for example not exceeding about 10 Å; and / or The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing of about 4 Å to about 50 Å, such as about 6 Å to 20 Å, for example about 8 Å to 10 Å.

61. The method of claim 54, wherein the adsorbent composition comprises the polyvalent anion in an amount of about 0.2 mmol to about 3 mmol, such as about 0.3 mmol to about 2.5 mmol, for example about 0.5 mmol to about 2 mmol per gram of covalent network solid oxide material.

62. The method of claim 54, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with a carbon atom of a nucleophilically susceptible linker precursor reactant to form a CO covalent bond.

63. The method of claim 62, wherein the linker precursor reactant comprises glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with the epoxy group of the glycidyltrimethylammonium cation to form the CO covalent bond.

64. The method of claim 54, wherein the covalent network solid oxide substrate material comprises one or more of silicon dioxide, aluminum oxide, cerium dioxide, zirconium oxide, iron oxide, and aluminosilicate.

65. The method according to claim 54, wherein: The polyvalent anion in the adsorbent composition includes oxygen and elements from Group 15 or Group 16 of the periodic table, for example, wherein the polyvalent anion is selected from: BO3 3- CO3 2 C2O4 2- SiO4 4- PO3 3- PO4 3- SO3 2- and SO4 2- ;and, The adsorbent composition for enriching the gas includes polyvalent anions, which include hydrogen, oxygen, and elements from Group 15 or Group 16 of the periodic table, for example, wherein the polyvalent anion is selected from HBO3. 2- HCO3 - HC2O4 - HSiO4 3- HPO3 2- HPO4 2- HSO3 - and HSO4 - ; The adsorbent composition for enriching the gas further comprises an anion of the formula (TG)OH-, wherein TG is the target gas, and wherein (TG)OH- - The polyvalent anion exists in a molar ratio of approximately 1:1; Optionally, the target gas is CO2, and (TG)OH - HCO 3- .

66. The method of claim 54, wherein the adsorbent composition comprises water, wherein the water is present in a water:polyvalent anion molar ratio of 1:10 to 40:1, such as 1:1 to 1:

20.

67. A method for removing a target gas from an adsorbent composition enriched with a target gas, wherein the method comprises contacting the adsorbent composition enriched with the target gas with a gas stream and water, wherein the gas stream has a first target gas concentration; The adsorbent composition for enriching the target gas comprises a covalent network solid oxide substrate material functionalized with ion-linking groups, wherein each ion-linking group comprises: polyvalent anions, and Polyatomic cations selected from ammonium, phosphorus, arsenic, antimony, bismuth, and sulfite; The polyatomic cations are covalently bonded to oxygen atoms on the surface of the substrate material; The target gas is released from the adsorbent composition enriched with the target gas, thereby forming a wetted adsorbent composition and a product stream having a second target gas concentration, wherein the second target gas concentration is higher than the first target gas concentration.

68. The method of claim 67, wherein the target gas is CO2.

69. The method of claim 67, wherein the polyatomic cation has the formula R(R'). x A + ,in: R is a hydrocarbon-containing group covalently bonded to an oxygen atom on the surface of the substrate material, or R is a covalent bond to an oxygen atom on the surface of the substrate material; and, Each R' is independently a hydrocarbon group or H; And among them: x is 3, and A is N, P, As, Sb, or Bi; or, x is 2, and A is S.

70. The method according to claim 69, wherein: R is an optionally substituted C1 to C8 hydrocarbon group; and / or, R' is a C1 to C6 alkyl group (such as methyl, ethyl, propyl, or butyl), or R' is an aryl group (such as phenyl).

71. The method of claim 67, wherein the polyatomic cation is ammonium, phosphonium, or sulfonium.

72. The method of claim 67, wherein the polyatomic cation is an ammonium cation, such as a quaternary ammonium cation, for example including cations containing trimethylammonium.

73. The method of claim 67, wherein: The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing not exceeding about 50 Å, such as not exceeding about 20 Å, for example not exceeding about 10 Å; and / or The polyatomic cations are spaced apart on the covalent network solid oxide material at an average spacing of about 4 Å to about 50 Å, such as about 6 Å to 20 Å, for example about 8 Å to 10 Å.

74. The method of claim 67, wherein the adsorbent composition for enriching the gas comprises the polyvalent anion in an amount of about 0.2 mmol to about 3 mmol, such as about 0.3 mmol to about 2.5 mmol, for example about 0.5 mmol to about 2 mmol per gram of covalent network solid oxide material.

75. The method of claim 67, wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with a carbon atom of a nucleophilically susceptible linker precursor reactant to form a CO covalent bond.

76. The method of claim 75, wherein the linker precursor reactant comprises glycidyltrimethylammonium cation, and wherein the substrate material is functionalized by reacting each of the oxygen atoms on the surface of the substrate material with the epoxy group of the glycidyltrimethylammonium cation to form the CO covalent bond.

77. The method of claim 67, wherein the covalent network solid oxide substrate material comprises one or more of silicon dioxide, aluminum oxide, cerium dioxide, zirconium oxide, iron oxide, and aluminosilicate.

78. The method of claim 67, wherein: The multivalent anions in the gas-enriching adsorbent composition include oxygen and elements from Group 15 or Group 16 of the periodic table, for example, wherein the multivalent anions are selected from: HBO3. 2- HCO3 - HC2O4 - HSiO4 3- HPO3 2- HPO4 2- HSO3 - and HSO4 - The adsorbent composition for enriching the gas further comprises the formula (TG)OH - The anion, wherein TG is the target gas, and wherein (TG)OH - The polyvalent anion exists in a molar ratio of approximately 1:1; and, The moistened adsorbent composition comprises polyvalent anions, including hydrogen, oxygen, and elements from Group 15 or Group 16 of the periodic table, for example, wherein the polyvalent anion is selected from BO3. 3- CO3 2 C2O4 2- SiO4 4- PO3 3- PO4 3- SO3 2- and SO4 2- ; Optionally, the target gas is CO2, and (TG)OH - HCO 3- .

79. The method of claim 67, wherein the moistened adsorbent composition comprises water in a molar ratio greater than 40:1, such as at least 50:1, of water to polyvalent anions.

80. The method of claim 67, further comprising drying the moistened adsorbent composition to form an adsorbent composition.

81. The method of claim 80, wherein the adsorbent composition comprises water, wherein the water is present in a water:polyvalent anion molar ratio of 1:10 to 40:1, such as 1:1 to 1:

20.

82. A method for processing a gas stream, comprising performing the method of claim 51 and subsequently performing the method of claim 63.

83. The method of claim 82, further comprising performing the method of claim 75 after performing the steps of the method of claim 63, and reusing the adsorbent composition thus formed to repeat the method of claim 51.

84. The method of claim 82, further comprising separating the target gas from the product stream.

85. A porous membrane for separating a target gas from a gas stream, wherein the porous membrane comprises the adsorbent composition according to claim 1.

86. The porous membrane according to claim 85, wherein the target gas is CO2.

87. The porous membrane according to claim 85, wherein it is composed of the adsorbent composition.

88. The porous membrane of claim 85, wherein the adsorbent composition is loaded on a membrane material, such as a polymer membrane material.

89. An apparatus for separating a target gas from a gas stream, wherein the apparatus comprises an adsorbent composition according to claim 1, wherein the adsorbent composition is arranged to contact the gas stream.

90. The apparatus of claim 89, wherein the target gas is CO2.

91. The device according to claim 89, comprising the porous membrane according to claim 85.

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