EP4770982A1

EP4770982A1 - Substrate with high porosity and low bulk density

Info

Publication number: EP4770982A1
Application number: EP24772796.9A
Authority: EP
Inventors: Guohua Chen
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2023-08-30
Filing date: 2024-08-27
Publication date: 2026-07-08
Also published as: CN121909174A; AU2024332984A1; WO2025049430A1

Abstract

A substrate includes an inorganic matrix including an interconnected pore structure. A total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³.

Description

SUBSTRATE WITH HIGH POROSITY AND LOW BULK DENSITY

Cross Reference to Related Application

[0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Serial No. 63/535342, filed on August 30, 2023, the content of which is relied upon and incorporated herein by reference in its entirety.

BACKGROUND

[0002] One method of removing CO2, either from a point source or from ambient air includes flowing the CO2 laden stream through a substrate containing a sorbent that adsorbs the CO2. The CO2 can later be desorbed for removal (e.g., via heating of the substrate).

However, the CO2 removal of conventional substrates can be constrained by the bulk density of the substrate (heat capacity) requiring more energy to heat for CO2 desorption.

Uimitations on the amount of sorbent that can be added to a substrate can also constrain the CO2 removal efficiency thereof.

SUMMARY OF THE INVENTION

[0003] Various aspects of the present disclosure provide a substrate that includes an inorganic matrix. The inorganic matrix includes an interconnected pore structure. A total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³.

[0004] Various aspects of the present disclosure provide a substrate that includes an inorganic matrix. The inorganic matrix includes an interconnected pore structure. The inorganic matrix can include interconnected burst-open hollow glass beads. A total pore volume of the matrix as determined by mercury porosimetry can be greater than or equal to 70% a bulk density is less than or equal to 0. 1 g/cm³ to 0.4 g/cm³. The substrate can further include a coating thereon. The coating can include a catalyst, sorbent that adsorbs and desorbs CO2, or a combination thereof. [0005] Various aspects of the present disclosure provide a substrate that is an extruded and fired product of an extrudable composition. The extrudable composition can include a binder and/or sintering aid. The extrudable composition can include hollow glass beads. The extrudable composition can also include graphite particles.

[0006] Various aspects of the present disclosure provide a substrate that is an extruded and fired product of an extruded extrudable composition. The extrudable composition includes a binder and/or sintering aid. The extrudable composition includes hollow glass beads. The extrudable composition also includes graphite particles. The substrate includes an inorganic matrix. The inorganic matrix includes an interconnected pore structure. A total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³. A majority or substantially all of the hollow glass beads break or burst during the firing.

[0007] Various aspects of the present disclosure provide a method of forming a substrate. The method includes extruding the extrudable composition. The method also includes firing the extruded composition, to form the substrate.

[0008] Various aspects of the present disclosure provide a method of forming a substrate. The method includes extruding an extrudable composition. The extrudable composition includes a binder and/or sintering aid. The extrudable composition includes hollow glass beads. The extrudable composition also includes graphite particles. The method also includes firing the extruded composition, to form the substrate. The substrate includes an inorganic matrix. The inorganic matrix includes an interconnected pore structure. A total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³. A majority or substantially all of the hollow glass beads break or burst during the firing.

[0009] Various aspects of the present disclosure provide a method of using a substrate of the present disclosure that includes a coating that includes a sorbent that adsorbs and desorbs CO2. The method includes exposing the substrate to a gas stream including CO2 to adsorb at least some of the CO2 from the gas-stream into the coating on the matrix. The method also includes desorbing the CO2 from the coating on the matrix, the desorbing including applying an electrical potential across the substrate to heat the substrate. [0010] Various aspects of the present disclosure provide a method of using a substrate of the present disclosure that includes a coating that includes a catalyst. The method includes exposing the substrate to a gas stream to catalyze a chemical reaction of one or more components of the gas stream using the catalyst.

[0011] The substrate of the present disclosure and inorganic matrix thereof can have greater porosity and/or lower density than other substrates, such as compared to other substrates formed from glass beads. The inorganic matrix of the substrate of the present disclosure can include greater porosity and/or lower density than other substrates formed from hollow glass beads, such as due to removal of graphite particles during firing. In various aspects of the present disclosure, the inclusion of graphite particles, a binder and/or sintering aid, or a combination thereof, into the extrudable composition can control and/or avoid shrinkage during firing. The substrate of the present disclosure and inorganic matrix thereof can be formed with less shrinkage of the extruded extrudable composition during firing as compared to other substrates formed from glass beads, providing greater porosity and/or lower density.

BRIEF DESCRIPTION OF THE FIGURES

[0012] The drawings illustrate generally, by way of example, but not by way of limitation, various aspects of the present disclosure.

[0013] FIG. 1 illustrates an example substrate having a honeycomb form according to various aspects disclosed herein.

[0014] FIG. 2 illustrates a plot of temperature versus time during a step of firing under nitrogen at 900 °C.

[0015] FIG. 3 illustrates a SEM image of a sample substrate having a composition including glass beads after firing.

[0016] FIG. 4 illustrates a SEM image of a sample substrate having a composition including glass beads after firing. DETAILED DESCRIPTION OF THE INVENTION

[0017] Reference will now be made in detail to certain aspects of the disclosed subject matter. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0018] Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

[0019] In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” or “at least one of A or B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section. [0020] In the methods described herein, the acts can be carried out in a specific order as recited herein. Alternatively, in any aspect(s) disclosed herein, specific acts may be carried out in any order without departing from the principles of the invention, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately or the plain meaning of the claims would require it. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process. [0021] The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

[0022] The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%. The term “substantially free of’ as used herein can mean having none or having a trivial amount of, such that the amount of material present does not affect the material properties of the composition including the material, such that about 0 wt% to about 5 wt% of the composition is the material, or about 0 wt% to about 1 wt%, or about 5 wt% or less, or less than, equal to, or greater than about 4.5 wt%, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt% or less, or about 0 wt%.

Substrate.

[0023] In various aspects, the present disclosure describes a porous substrate. The substrate includes an inorganic matrix. The inorganic matrix can be a glass matrix, a ceramic matrix, or a combination thereof. The inorganic matrix includes an interconnected pore structure. A total pore volume of the matrix as determined by mercury porosimetry can be greater than or equal to 70%. A bulk density of the matrix as determined by mercury porosimetry can be less than or equal to 0.4 g/cm³. Mercury porosimetry, such as for determining total pore volume and/or bulk density, can be performed as per ASTM D6761-07 (2012). In various aspects, the substrate can be a monolithic substrate (e.g., a substrate formed from a single continuous extruded form). In various aspects, the substrate can be a plurality of monolithic substrates (e.g., a substrate formed from a placing two or more single continuous extruded forms together).

[0024] The matrix can have any suitable bulk density. Bulk density is the mass of the matrix divided by the total volume that the matrix occupies, wherein the total volume the matrix occupies includes particle volume, inter-particle void volume, and internal pore volume (intraparticle void), but does not include longitudinal channels (e.g., portions of the matrix when viewed from a longitudinal end of the matrix that are considered to be open frontal area). The total volume that a matrix with a honeycomb form occupies can be defined as the portions of the matrix when viewed from a longitudinal end of the matrix that is considered to be closed frontal area (CFA) versus those of the open frontal area (OFA), with the CFA and OFA given as complementary percentages that sum to 100%. In particular, the OFA corresponds to the portions of the cross-sectional area occupied by the open channels of the honeycomb form of the matrix, while the CFA corresponds to the remaining portions occupied by the matrix of intersecting walls. For example, the matrix (e.g., absent any coatings added thereto) can have a bulk density of less than or equal to 0.4 g/cm³, or 0. 1 g/cm³ to 0.4 g/cm³, or 0. 15 g/cm³ to 0.35 g/cm³, or less than or equal to 0.4 g/cm³ and greater than or equal to 0. 1 g/cm³ and less than, equal to, or greater than 0. 1 g/cm³, 0. 13, 0.15, 0. 17, 0.2, 0.23, 0.25, 0.27, 0.3, 0.33, 0.35, or 0.37 g/cm³. The matrix (e.g., absent any coatings added thereto) can have any suitable total pore volume, as determined via mercury porosimetry, such as greater than or equal to 70%, or 70% to 95%, or 80% to 90%, or less than or equal to 95% and greater than or equal to 70% and less than, equal to, or greater than 71%, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, or 94%. As used herein, total pore volume only includes pores that can be reached during mercury porosimetry and does not include closed pores.

[0025] The substrate and the inorganic matrix of the substrate can have any suitable physical form. In various aspects, the physical form is that of a honeycomb form (e.g., an extruded honeycomb form), having a plurality of cells therein, the cells that define parallel channels running longitudinally through the honeycomb form. The cells can be formed by an array or matrix of intersecting walls (e.g., the inorganic matrix). An example of a porous substrate 100 having a honeycomb form is shown in FIG. 1. For example, a honeycomb form can be achieved by extruding a mixture (which may be referred to as a batch mixture) through a corresponding honeycomb extrusion die. After extrusion, the green body can be dried and/or fired. For example, firing can be utilized in order to react ceramic precursor particles into one or more ceramic phases and/or to sinter particles together to form a glass and/or ceramic material as described herein.

[0026] As shown in FIG. 1, the substrate 100 extends in an axial direction 105 between a first end face 101 and a second end face 103. The substrate 100 comprises a plurality of porous walls 102 made of the ceramic and/or glass material as described further herein. The porous walls 102 are arranged in an intersecting array and define a plurality of channels 104 extending axially through the substrate 100. Accordingly, the first end 101 may receive a fluid flow, such as a carbon dioxide containing flow if used in a carbon capture system or an exhaust flow if used with a catalytic conversion system, and the fluid flow travels through the substrate 100 via the channels 104 and is expelled out from the second end 103. In the example of FIG. 1, the channels 104 of the substrate 100 are cross-sectionally square.

However, in other examples, the channels 104 may be differently shaped, such as hexagonal, triangular, or some other shape.

[0027] In the example of FIG. 1, the substrate 100 is depicted as substantially cylindrical (having a circular cross-section). However, in other examples, the substrate 100 may be any appropriate shape. For example, the substrate 100 may be shaped as rectangular blocks to facilitate the stacking thereof into an array suitable for a large scale carbon dioxide capture system. The cross-sectional shape can be defined with respect to one or more lateral directions. That is, by lateral direction it is meant directions that extend perpendicular to the axial direction. Accordingly, a lateral direction can be defined as any direction perpendicular to the axial direction. For example, a lateral direction 107 is labeled in FIG. 1, which corresponds to the radial direction of the cylindrical shape that is illustrated.

[0028] The honeycomb form can have any suitable circumferential profile or shape, such as that of a circle, oval, square, rectangle, hexagon, triangle, polygon, or irregular shape. When viewed from an end of the honeycomb form, the cells can have any suitable profile, such as a profile of a circle, oval, square, rectangle, hexagon, triangle, polygon, or irregular shape, such as a honeycomb shape. For example, one possible combination is a cylindrical substrate (circular circumferential profile) that has square-shaped cells. The use of a honeycomb form can advantageously result in a lower pressure drop of a fluid stream flowing from one axial end of the matrix to the other end in comparison to other forms (such as packed pellet beds). The honeycomb form can include any suitable number of cells per square inch (e.g., as measured when viewed from an end), such as 20 to 1000 cells per square inch, or 50 to 600, or less than or equal to 1000 cells per square inch and greater than or equal to 20 squares per square inch and less than, equal to, or greater than 40 squares per square inch, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 260, 280, 300, 320, 340, 360, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, or 950 cells per square inch. The cells in the honeycomb form have any suitable wall thickness, such as a wall thickness of 0.001 inches to 0. 1 inches, or 0.002 inches to 0.05 inches, or less than or equal to 0. 1 inches and greater than or equal to 0.001 inches and less than, equal to, or greater than 0.002 inches, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, 0.01, 0.011, 0.012, 0.013, 0.014, 0.015, 0.016, 0.017, 0.018, 0.019, 0.02, 0.025, 0.03, 0.035, 0.04, or 0.045 inches. In various aspects, the cells in the honeycomb form can include a geometry of 100/8 or 200/8 cells per square inch/0.001” wall thickness.

[0029] The substrate can have any suitable open frontal area. The open frontal area (or OFA) is the percent cross-sectional area of the longitudinal channels in the honeycomb form that is, for example, available for gas to flow therethrough. In contrast, the closed frontal area (or CFA) is the percent cross-sectional (perpendicular to the axial or longitudinal direction) area of the intersecting walls of the matrix (i.e., excluding the open frontal area). For example, the substrate can have an open frontal area of 70-95%, 75-90%, 78-85%, or less than 95% and greater than or equal to 70% and less than, equal to, or greater than 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, or 94%.

[0030] The substrate can optionally include a coating on the matrix (e.g., on the matrix, in the matrix, or a combination thereof) including a catalyst, a sorbent that adsorbs and desorbs CO2, another functional material, or a combination thereof. In various aspects, the coating can be directly adhered to the material of the inorganic matrix, wherein the substrate is free of an intervening bonding layer between the coating and the material of the inorganic matrix. However, in various aspects, the substrate can include a bonding layer between the coating and the material of the inorganic matrix. The bonding layer can be any suitable bonding layer. The bonding layer can be a washcoat material. The bonding layer can include a deposition of high surface area particles, such as gamma alumina, zeolite, activated carbon, or a combination thereof. The coating that includes a catalyst can be the catalyst or can include one or more other components. The coating that includes the sorbent can be the sorbent or can include one or more other components. The sorbent can be any suitable sorbent that adsorbs and desorbs CO2, such as a zeolite, sodium carbonate, activated carbon, carbon nanotubes, a metal-organic framework (MOF), an amine, or a combination thereof. The substrate including a coating including a sorbent and/or catalyst can include any suitable loading level of the sorbent or of the catalyst, such as 0.1 wt% to 99% (e.g., wherein 0. 1 wt% to 99 wt% of the substrate including the coating is the sorbent or catalyst), 1 wt% to 90 wt%, or less than or equal to 99% and greater than or equal to 0.1 wt% and less than, equal to, or greater than 1 wt%, 2, 4, 6, 8, 10, 12, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 82, 84, 86, 88, 90, 91, 92, 93, 94, 95, 96, 97, or 98 wt%.

[0031] The substrate can be substantially free of hollow glass beads that have not been burst and/or broken. For example, the substrate can be substantially free of hollow glass beads that have not burst and/or broken during a firing step to form the substrate. For example, unbroken and unburst hollow glass beads can be 0 wt% of the substrate, or equal to or less than 5 wt%, 4, 3, 2, 1, 0.5 wt%, or equal to or less than 0. 1 wt%, or 0 wt% to 5 wt% of the substrate, or less than or equal to 5 wt% and greater than or equal to 0 wt%, 0.01, 0. 1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, or 4.5 wt%.

[0032] In various aspects, the substrate of the present disclosure can be an extruded and fired product of an extrudable composition. The extrudable composition can include a binder and/or sintering aid. The extrudable composition can include hollow glass beads. The extrudable composition can also include graphite particles. The extrudable composition can be an extrudable paste including the foregoing ingredients combined with a liquid component, such as water, oils, fatty acids, or other extrusion aids or lubricants.

[0033] The binder and/or sintering aid can be any suitable binder and/or sintering aid. For example, the binder can include an organic binder, an inorganic binder, cellulose, a cellulose derivative, a polymer, a thermosetting resin, a carbon precursor, or a combination thereof. The binder can include a cellulose derivative. In various aspects, the sintering aid can include a borate, a phosphate, a transition metal oxide, an oxide, a hydroxide, a carbonate, a silicate, an alumino-silicate, or a combination thereof. The sintering aid can include talc, clay, MgO, alumina, or a combination thereof. The cellulose derivative can include (Ci-C3)alkylhydroxy(Ci-C3)alkyl cellulose, or a (Ci-C3)alkylhydroxy cellulose, or a (Ci-C3)alkylcellulose, or a (Ci-C3)alkyl(Ci-C3)alkylcellulose or methylhydroxypropyl cellulose, methylhydroxyethyl cellulose, methylhydroxymethyl cellulose, methylcellulose, ethylcellulose, propylcellulose, hydroxypropylcellulose, methylethyl cellulose, sodium carboxymethylcellulose, or a combination thereof. The binder and/or sintering aid can be 0 wt% to 30 wt% of the extrudable composition based on a dry weight of the extrudable composition, such as 5 wt% to 30 wt%, 10 wt% to 15 wt%, or less than or equal to 30 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 1 wt%, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29 wt%.

The binder can be 0 wt% to 30 wt% of the extrudable composition based on a dry weight of the extrudable composition, such as 1 wt% to 15 wt%, or less than or equal to 30 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 1 wt%, 2, 3, 4, 5, 6, 7,

8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29 wt%. The sintering aid can be 0 wt% to 30 wt% of the extrudable composition based on a dry weight of the extrudable composition, such as 1 wt% to 15 wt%, or less than or equal to 30 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 1 wt%, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, or 29 wt%. [0034] The hollow glass beads can have any suitable dso diameter, such as a dso diameter of 10 microns to 100 microns, 20 microns to 80 microns, or less than or equal to 100 microns and greater than or equal to 10 microns and less than, equal to, or greater than 15 microns, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 microns. As used herein a dso diameter is an average particle size by mass, such that the dso diameter of a material is both smaller than 50% of the material by mass and that is also larger than 50% of the material by mass. The hollow glass beads can be 30 wt% to 90 wt% of the extrudable composition based on a dry weight of the extrudable composition, or 50 wt% to 70 wt%, or less than or equal to 90 wt% and greater than or equal to 30 wt% and less than, equal to, or greater than 35 wt%, 40, 42, 44, 46, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 72, 74, 76, 78, 80, or 85 wt%.

[0035] The graphite particles can be any suitable type of graphite, such as natural graphite, synthetic graphite, or a combination thereof. The graphite particles can have a largest dimension, or a dso, of 0.1 microns to 50 microns, or 1 micron to 30 microns, or less than or equal to 50 microns and greater than or equal to 0.1 micron and less than, equal to, or greater than 0.5 micron, 1, 2 microns, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, or 28 microns. The graphite particles can be 5 wt% to 80 wt% of the extrudable composition, based on a dry weight of the extrudable composition, such as 15 wt% to 40 wt%, or less than or equal to 80 wt% and greater than or equal to 5 wt% and less than, equal to, or greater than 10 wt%, 15, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 45, 50, 55, 60, 65, 70, or 75 wt%.

[0036] In various aspects, the graphite particles in the extrudable composition can be substantially oxidized and removed in the substrate, such as during a firing step. For example, the graphite particles can be 0 wt% of the substrate, or equal to or less than 5 wt%, 4, 3, 2, 1, 0.5 wt%, or equal to or less than 0. 1 wt%, or 0 wt% to 5 wt% of the substrate, or less than or equal to 5 wt% and greater than or equal to 0 wt%, 0.01, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, or 4.5 wt%.

[0037] The extrudable composition can include any suitable one or more optional components. For example, the extrudable composition can further include a surfactant (e.g., sodium stearate), a lubricant (e.g., a lubricating oil), or a combination thereof. The one or more optional components can form any suitable proportion of the extrudable composition, on a dry weight basis, such as 0 wt% to 30 wt%, 0 wt% to 10 wt%, or 1 wt% to 5 wt%, or less than or equal to 10 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.1 wt%, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, or 28 wt%. [0038] The extrudable composition can further include one or more solvents. The one or more solvents can include an aqueous solvent (e.g., including water), an organic solvent, an oil, or a combination thereof. The solvent can form any suitable proportion of the extrudable composition, such as 10 wt% to 80 wt%, or 30 wt% to 50 wt%, or less than or equal to 80 wt% and greater than or equal to 10 wt% and less than, equal to, or greater than 15 wt%, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75 wt%.

Method of forming a substrate.

[0039] Various aspects of the present disclosure provide a method of forming a substrate. The method can include extruding the extrudable composition described herein, wherein the extrudable composition includes the binder and/or sintering aid, the hollow glass beads, and the graphite particles. The method can also include firing the extruded composition, to form the substrate.

[0040] The method can further include drying the extruded composition. The drying can be any suitable drying that removes a majority or substantially all solvent from the extruded composition. The drying can be combined with the firing step (e.g., the firing can dry the extruded composition), or the drying can be an independent step from the drying step (e.g., drying is performed prior to the firing). The drying can include heating the extruded composition (e.g., by exposing the extruded composition to a heat source) and/or exposing the extruded composition to microwaves. The drying can include placing the extruded composition under a vacuum. The drying can include a combination placing the extruded composition under a vacuum and heating the extruded composition.

[0041] The firing can be any suitable firing that sinters extruded composition to form the inorganic matrix of the substrate. The firing can cause sintering of the binder and/or sintering aid. The firing can cause hollow glass beads in the extruded extrudable composition to break and/or burst. The firing can cause graphite in the extruded extrudable composition to oxidize and/or be removed during the firing. In some aspects, the firing can break and/or burst the hollow glass beads without oxidizing and/or removing the graphite, such as by firing under an inert atmosphere. The firing can include heating the extruded extrudable composition to a firing temperature of 600 °C to 1100 °C, or 800 °C to 950 °C, or 820 °C to 870 °C, or 875 °C to 925 °C, or less than or equal to 1100 °C and greater than or equal to 600 °C and less than, equal to, or greater than 620 °C, 640, 660, 680, 700, 720, 740, 760, 780, 800, 810, 820, 830, 840, 850, 860, 870, 880, 890, 900, 910, 920, 930, 940, 950, 960, 970, 980, 990, 1000, 1020, 1040, 1060, or 1080 °C. The firing can be conducted under air or inert gas (e.g., argon and/or nitrogen). The firing can include firing under nitrogen, and then firing under air. To effectively remove the graphite particles, the firing can include firing under air or other oxygenated atmosphere to provide oxidation and removal of the graphite particles. The firing including firing under an inert gas such as nitrogen at a firing temperature of 600 °C to 1100 °C and then firing under air at a firing temperature of 600 °C to 1100 °C. The firing under inert gas can break or burst a majority of or substantially all of the hollow glass beads without burning out or destroying the graphite particles. The subsequent firing under air can bum out the graphite particles. The firing can be conducted for any suitable duration. For example, the firing can include firing at a firing temperature for a duration of 0 minutes to 1 hour, or less than or equal to 1 h and greater than or equal to 1 min and less than, equal to, or greater than 2 min, 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, or 58 min. The firing can include ramping temperature up to a firing temperature and/or down from a firing temperature at any suitable rate, such as a rate of 10 °C/h to 800 °C/h, or 100 °C/h to 600 °C/h, or less than or equal to 800 °C/h and greater than or equal to 10 °C/h and less than, equal to, or greater than 20 °C/h, 40, 60, 80, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 750, 700, or 750 °C/h. In various aspects, the firing under the inert gas is conducted at a higher temperature than the firing under air.

[0042] As compared to the extruded composition (e.g., the extruded product that has been dried), the substrate can have a shrinkage (e.g., a reduction in size as measured along one edge of the substrate) of 0% to 6%, or 0% to 2%, or less than or equal to 6% and greater than or equal to 0% and less than, equal to, or greater than 0.01%, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1, 1.2, 1.4, 1.6, 1.8, 2, 2.5, 3, 3.5, 4, 4.5, 5, or 5.5%.

Method of using a substrate.

[0043] Various aspects of the present disclosure provide a method of using the substrate that includes a coating on the matrix that includes a sorbent that can adsorb and desorb CO2. The method can include exposing the substrate to a gas stream that includes CO2 to adsorb at least some of the CO2 from the gas stream. The method can also include desorbing the CO2 from the coating on the matrix. In various aspects, desorbing the CO2 from the coating on the matrix includes heating the substrate, such as via resistive heating, sending hot gas (e.g., steam) through the substrate, microwave heating, induction heating, via an external heat source at a periphery of the substrate, or a combination thereof. In various aspects, the method can further include sequestering the CO2, such as placing the CO2 in a storage tank.

[0044] The methods of using the substrate described herein can be used for any suitable method of CCh-rcmoval. such as direct air capture (DAC) or capture of CO2 at an effluent source. In various aspects, the substrate described herein can be capable of withstanding temperatures of 200 °C or more and withstanding moist environments.

[0045] Various aspects of the present disclosure provide a method of using the substrate that includes a coating thereon that includes a catalyst. The method can include exposing the substrate to a gas stream to catalyze a chemical reaction of one or more components of the gas stream using the catalyst. Examples

[0046] Various aspects of the present disclosure can be better understood by reference to the following Examples which are offered by way of illustration. The present disclosure is not limited to the Examples given herein.

[0047] In the Examples, the firing is performed in two steps. A first step is firing under nitrogen at 900 °C to allow glass bubbles to open to release their internal porosity. Graphite is included as a filler to control shrinkage. A second step is firing in air above 800 °C to remove graphite, which releases volume occupied by the graphite to obtain an even higher porosity, while removing weight contributed by the graphite to obtain even lower bulk density.

[0048] FIG. 2 illustrates a plot of temperature versus time during the first step of firing under nitrogen at 900 °C. During the first step, temperature was ramped from ambient temperature up to 900 °C at 400°C/h, and then the temperature was cooled down to ambient temperature at 400°C/h. The entirety of the first step was performed under nitrogen. In step 2, the material was fired in air above 800 °C for one hour to remove graphite. In the present examples, 870 °C was used in the second step for samples Composition A and Composition B, while 820 °C was used in the second step for all other samples. The entirety of the second step was performed under air.

[0049] Three different types of glass bubbles were used in the Example compositions herein, as shown in Table 1.

[0050] Tab: e 1 . Types of glass bubbles used in the Examples.

[0051] The glass bubbles were supplied by the Zhongke Yali company. The graphite used was Asbury 4014. All samples in the Examples were formed to 1-inch square honeycombs with 300 cells per square inch and 8 mil wall thickness. The Examples herein obtained fired honeycombs having a porosity in the range of 84.47% to 89.25% and a bulk density in the range of 0.35 g/cm³ to 0.19 g/cm³. Porosity was total pore volume as measured by mercury porosimetry. Bulk density was measured by mercury porosimetry. Mercury porosimetry was performed as per ASTM D6761-07 (2012). The binder Culminal 724 was methylhydroxypropyl cellulose.

Example 1. H60 glass bubbles.

[0052] Table 2 lists two compositions, Composition A and Composition B, that were made with H60 glass bubbles. Both binder and water in Table 2 are listed in terms of parts added to 100 parts H60 and graphite. Both samples were sintered at 900 °C under nitrogen, then fired at 870 °C in air. The porosity and bulk density of the samples after the firing is shown in Table 3.

[0053] Table 2, Example 1 compositions.

[0054] Table 3 Porosity and bulk density of fired Example 1 compositions.

[0055] FIG. 3 illustrates a SEM image of a substrate made in accordance with the Composition A sample after firing.

Example 2, H46 glass bubbles.

[0056] Table 4 lists two compositions, Composition C and Composition D, that were made with H46 glass bubbles. Both binder and water in Table 4 are listed in terms of parts added to 100 parts H46 and graphite. Both samples were sintered at 900 °C under nitrogen, then fired at 820 °C in air. The porosity and bulk density of the samples after the firing is shown in Table 5. [0057] Table 4, Example 2 compositions.

[0058] Table 5 Porosity and bulk density of fired Example 2 compositions.

Example 3, H38 glass bubbles.

[0059] Table 6 lists two compositions, Composition E and Composition F, that were made with H38 glass bubbles. Both binder and water in Table 6 are listed in terms of parts added to 100 parts H38 and graphite. Both samples were sintered at 900 °C under nitrogen, then fired at 820 °C in air. The porosity and bulk density of the samples after the firing is shown in Table 5.

[0060] Table 6, Example 3 compositions.

[0061] Table 7. Porosity and bulk density of fired Example 3 compositions .

[0062] FIG. 4 illustrates a SEM image of a substrate made in accordance with the Composition E sample after firing. The scale bar represents 150 microns. [0063] The terms and expressions that have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the aspects of the present disclosure. Thus, it should be understood that although the present disclosure has been specifically disclosed by specific aspects and optional features, modification and variation of the concepts herein disclosed may be resorted to by those of ordinary skill in the art, and that such modifications and variations are considered to be within the scope of aspects of the present disclosure.

Exemplary Aspects.

[0064] The following exemplary aspects are provided, the numbering of which is not to be construed as designating levels of importance:

[0065] Aspect 1 provides a substrate comprising: an inorganic matrix comprising an interconnected pore structure, wherein a total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³.

[0066] Aspect 2 provides the substrate of Aspect 1, wherein the total pore volume is 70% to 95%.

[0067] Aspect 3 provides the substrate of any one of Aspects 1-2, wherein the total pore volume is 80% to 90%.

[0068] Aspect 4 provides the substrate of any one of Aspects 1-3, wherein the bulk density of the matrix is 0.1 g/cm³ to 0.4 g/cm³.

[0069] Aspect 5 provides the substrate of any one of Aspects 1-4, wherein the bulk density of the matrix is 0.15 g/cm³ to 0.35 g/cm³.

[0070] Aspect 6 provides the substrate of any one of Aspects 1-5, wherein the substrate has a shape of a honeycomb form having a plurality of cells therein, the cells comprising parallel channels running longitudinally through the honeycomb form.

[0071] Aspect 7 provides the substrate of Aspect 6, wherein the honeycomb form has a circumferential profile of a circle, oval, square, rectangle, hexagon, triangle, polygon, or irregular shape. [0072] Aspect 8 provides the substrate of any one of Aspects 6-7, wherein cells of the honeycomb form have a profile of a circle, oval, square, rectangle, hexagon, triangle, polygon, or irregular shape when viewed from an end of the honeycomb form.

[0073] Aspect 9 provides the substrate of any one of Aspects 1-8, wherein the matrix comprises a coating thereon, the coating comprising a catalyst, a sorbent that adsorbs and desorbs CO2, or a combination thereof.

[0074] Aspect 10 provides the substrate of Aspect 9, wherein the sorbent comprises a zeolite, sodium carbonate, activated carbon, carbon nanotubes, a metal-organic framework (MOF), an amine, or a combination thereof.

[0075] Aspect 11 provides the substrate of any one of Aspects 9-10, wherein the coating is directly adhered to the interconnected pore structure, wherein the substrate is free of an intervening layer between the coating and the inorganic matrix.

[0076] Aspect 12 provides the substrate of any one of Aspects 9-11, wherein the substrate comprises a washcoat between the interconnected pore structure and the coating that comprises the sorbent.

[0077] Aspect 13 provides the substrate of Aspect 12, wherein the washcoat comprises gamma alumina, zeolite, activated carbon, or a combination thereof.

[0078] Aspect 14 provides the substrate of any one of Aspects 12-13, wherein the washcoat comprises gamma alumina.

[0079] Aspect 15 provides the substrate of any one of Aspects 1-14, wherein the substrate is substantially free of hollow glass beads that have not been burst and/or broken.

[0080] Aspect 16 provides a substrate comprising: an inorganic matrix comprising an interconnected pore structure, wherein a total pore volume of the matrix as determined by mercury porosimetry is 75% to 95% and a bulk density of the matrix is less than or equal to 0. 1 g/cm³ to 0.4 g/cm³; wherein the matrix comprises a coating thereon, the coating comprising a sorbent that adsorbs and desorbs CO2.

[0081] Aspect 17 provides the substrate of any one of Aspects 1-16, wherein the substrate or matrix is an extruded and fired product of an extrudable composition, the extrudable composition comprising: a binder and/or sintering aid; hollow glass beads; and graphite particles.

[0082] Aspect 18 provides the substrate of Aspect 17, wherein in the substrate a majority or substantially all of the hollow glass beads have broken or burst during the firing. [0083] Aspect 19 provides the substrate of any one of Aspects 17-18, wherein as compared to the extruded product, the substrate or matrix has a reduction in size as measured along an edge thereof of 0%to 6%.

[0084] Aspect 20 provides the substrate of any one of Aspects 17-19, wherein as compared to the extruded product, the substrate or matrix has a reduction in size as measured along an edge thereof of 0% to 2%.

[0085] Aspect 21 provides the substrate of any one of Aspects 17-20, wherein the binder and/or sintering aid is 0 wt% to 30 wt% of the extrudable composition, or 5 wt% to 30 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0086] Aspect 22 provides the substrate of any one of Aspects 17-21, wherein the binder and/or sintering aid is 10 wt% to 15 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0087] Aspect 23 provides the substrate of any one of Aspects 17-22, wherein the binder comprises an inorganic binder, organic binder, a polymer, a thermosetting resin, a carbon precursor, cellulose, a cellulose derivative, or a combination thereof. The binder can comprise a cellulose derivative.

[0088] Aspect 24 provides the substrate of any one of Aspects 17-23, wherein the sintering aid comprises a borate, a phosphate, a transition metal oxide, an oxide, a hydroxide, a carbonate, a silicate, an alumino-silicate, or a combination thereof. The sintering aid can comprise talc, clay, MgO, alumina, or a combination thereof.

[0089] Aspect 25 provides the substrate of any one of Aspects 17-24, wherein the hollow glass beads have a dso diameter of 10 microns to 100 microns.

[0090] Aspect 26 provides the substrate of any one of Aspects 17-25, wherein the hollow glass beads have a dso diameter of 20 microns to 80 microns.

[0091] Aspect 27 provides the substrate of any one of Aspects 17-26, wherein the hollow glass beads are 30 wt% to 90 wt% of the extrudable composition, based on a dry weight of the extrudable composition. [0092] Aspect 28 provides the substrate of any one of Aspects 17-27, wherein the hollow glass beads are 50 wt% to 70 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0093] Aspect 29 provides the substrate of any one of Aspects 17-28, wherein the graphite particles are 5 wt% to 80 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0094] Aspect 30 provides the substrate of any one of Aspects 17-29, wherein the graphite particles are 15 wt% to 40 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0095] Aspect 31 provides the substrate of any one of Aspects 17-30, wherein the graphite particles comprise natural graphite, synthetic graphite, or a combination thereof.

[0096] Aspect 32 provides the substrate of any one of Aspects 17-31, wherein the graphite particles have a dso that is smaller than a dso of the hollow glass beads.

[0097] Aspect 33 provides the substrate of any one of Aspects 17-32, wherein the graphite particles have a largest dimension of 0. 1 microns to 50 microns.

[0098] Aspect 34 provides the substrate of any one of Aspects 17-33, wherein the graphite particles have a largest dimension of 1 microns to 30 microns.

[0099] Aspect 35 provides the substrate of any one of Aspects 17-34, wherein the graphite particles in the extrudable composition are substantially oxidized and removed in the substrate.

[0100] Aspect 36 provides the substrate of any one of Aspects 17-35, wherein the extrudable composition further comprises a surfactant, a lubricant, an oil, or a combination thereof.

[0101] Aspect 37 provides the substrate of any one of Aspects 17-36, wherein the extrudable composition further comprises one or more solvents.

[0102] Aspect 38 provides a substrate comprising: an extruded and fired product of an extruded extrudable composition, the extrudable composition comprising a binder and/or sintering aid; hollow glass beads; and graphite particles; wherein the substrate comprises an inorganic matrix comprising an interconnected pore structure, wherein a total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³, and wherein in the substrate a majority or substantially all of the hollow glass beads have broken or burst during the firing.

[0103] Aspect 39 provides a method of forming the substrate of any one of Aspects 17-38, the method comprising: extruding the extrudable composition; and firing the extruded composition, to form the substrate.

[0104] Aspect 40 provides the method of Aspect 39, further comprising drying the extruded composition, wherein the drying comprises heating, exposing to microwaves, placing the extruded composition under a vacuum, or a combination thereof.

[0105] Aspect 41 provides the method of any one of Aspects 39-40, wherein the firing comprises firing at a firing temperature of 600 °C to 1100 °C.

[0106] Aspect 42 provides the method of any one of Aspects 39-41, wherein the firing comprises firing at a firing temperature of 800 °C to 950 °C.

[0107] Aspect 43 provides the method of any one of Aspects 39-42, wherein the firing comprises firing under nitrogen at a firing temperature of 600 °C to 1100 °C.

[0108] Aspect 44 provides the method of any one of Aspects 39-43, wherein the firing comprises firing under air at a firing temperature of 600 °C to 1100 °C.

[0109] Aspect 45 provides the method of Aspect 44, wherein the firing under air is sufficient to oxidize and remove a majority or substantially all of the graphite.

[0110] Aspect 46 provides the method of any one of Aspects 39-45, wherein the firing comprising firing under nitrogen at a firing temperature of 600 °C to 1100 °C and then firing under air at a firing temperature of 600 °C to 1100 °C.

[0111] Aspect 47 provides the method of Aspect 46, wherein a majority or substantially all of the hollow glass beads break or burst during the firing under inert gas without burning out the graphite particles, wherein a majority or substantially all of the graphite particles bum out during the firing under air.

[0112] Aspect 48 provides the method of any one of Aspects 46-47, wherein the firing under air is conducted at a lower temperature than the firing under inert gas. [0113] Aspect 49 provides the method of any one of Aspects 39-48, wherein the firing comprises firing at a firing temperature for a duration of 0 minutes to 1 hour.

[0114] Aspect 50 provides the method of any one of Aspects 39-49, wherein the firing comprises ramping temperature up to a firing temperature and/or down from a firing temperature at a rate of 10°C/h to 800°C/h.

[0115] Aspect 51 provides the method of any one of Aspects 39-50, wherein the firing comprises ramping temperature up to a firing temperature and/or down from a firing temperature at a rate of 100°C/h to 600°C/h.

[0116] Aspect 52 provides a method of forming a substrate, the method comprising: extruding an extrudable composition, the extrudable composition comprising a binder and/or sintering aid, hollow glass beads, and graphite particles; and firing the extruded composition, to form the substrate comprising an inorganic matrix comprising an interconnected pore structure, wherein a total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³, and wherein in the substrate a majority or substantially all of the hollow glass beads have broken or burst during the firing.

[0117] Aspect 53 provides a method of using the substrate of any one of Aspects 9-14 and 16, the method comprising: exposing the substrate to a gas stream including CO2 to adsorb at least some of the CO2 from the gas stream into the coating on the matrix; and desorbing the CO2 from the coating on the matrix, the desorbing comprising applying an electrical potential across the substrate to heat the substrate.

[0118] Aspect 54 provides a method of using the substrate of any one of Aspects 9- 14, the method comprising: exposing the substrate to a gas stream to catalyze a chemical reaction of one or more components of the gas stream using the catalyst.

[0119] Aspect 55 provides the substrate or method of any one or any combination of Aspects 1-54 optionally configured such that all elements or options recited are available to use or select from.

Claims

CLAIMS What is claimed is:

1. A substrate comprising: an inorganic matrix comprising an interconnected pore structure, wherein a total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³.

2. The substrate of claim 1, wherein the total pore volume is 70% to 95% and the bulk density of the matrix is 0.1 g/cm³ to 0.4 g/cm³.

3. The substrate of any one of claims 1-2, wherein the substrate has a shape of a honeycomb form comprising a plurality of cells therein, the cells defining parallel channels running longitudinally through the honeycomb form.

4. The substrate of any one of claims 1-3, wherein the matrix comprises a coating thereon, the coating comprising a catalyst, a sorbent that adsorbs and desorbs CO2, or a combination thereof.

5. The substrate of claim 4, wherein the substrate comprises a washcoat between the matrix and the coating that comprises the sorbent, wherein the washcoat comprises gamma alumina, zeolite, activated carbon, or a combination thereof.

6. The substrate of any one of claims 1-5, wherein the substrate is an extruded and fired product of an extrudable composition, the extrudable composition comprising: a binder and/or sintering aid; hollow glass beads; and graphite particles.

7. The substrate of claim 6, wherein in the substrate a majority of the hollow glass beads have broken or burst during the firing.

8. The substrate of any one of claims 6-7, wherein in the substrate a majority of the graphite particles have been oxidized and/or removed during the firing.

9. The substrate of any one of claims 6-8, wherein as compared to the extruded product, the substrate has a reduction in size as measured along an edge thereof of 0% to 6%.

10. The substrate of any one of claims 6-9, wherein the binder and/or sintering aid is 5 wt% to 30 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

11. The substrate of any one of claims 6-10, wherein the binder comprises an inorganic binder, organic binder, a polymer, a thermosetting resin, a carbon precursor, cellulose, a cellulose derivative, or a combination thereof.

12. The substrate of any one of claims 6-11, wherein the binder and/or sintering aid comprises talc, clay, MgO, alumina, a borate, a phosphate, a transition metal oxide, an oxide, a hydroxide, a carbonate, a silicate, an alumino-silicate, or a combination thereof.

13. The substrate of any one of claims 6-12, wherein the hollow glass beads have a dso diameter of 10 microns to 100 microns, the graphite particles have a dso of 0. 1 microns to 50 microns, and wherein the dso of the graphite particles is smaller than the dso of the hollow glass beads.

14. The substrate of any one of claims 6-13, wherein the hollow glass beads are 30 wt% to 90 wt% of the extrudable composition, and the graphite particles are 5 wt% to 80 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

15. A substrate comprising: an extruded and fired product of an extruded extrudable composition, the extrudable composition comprising a binder and/or sintering aid; hollow glass beads; and graphite particles; wherein the substrate comprises an inorganic matrix comprising an interconnected pore structure, wherein a total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³, and wherein in the substrate a majority of the hollow glass beads have broken or burst during the firing.

16. A method of forming the substrate of any one of claims 1-15, the method comprising: extruding the extrudable composition; and firing the extruded composition, to form the substrate.

17. The method of claim 16, wherein the firing comprises firing under air at a firing temperature of 600 °C to 1100 °C.

18. The method of any one of claims 16-17, wherein the firing comprising firing under inert gas at a firing temperature of 600 °C to 1100 °C and then firing under air at a firing temperature of 600 °C to 1100 °C.

19. The method of claim 18, wherein a majority of the hollow glass beads break or burst during the firing under inert gas without burning out the graphite particles, wherein a majority of the graphite particles bum out during the firing under air.

20. The method of any one of claims 18-19, wherein the firing under air is conducted at a lower temperature than the firing under inert gas.

21. A method of forming a substrate, the method comprising: extruding an extrudable composition, the extrudable composition comprising a binder and/or sintering aid, hollow glass beads, and graphite particles; and firing the extruded composition, to form the substrate comprising an inorganic matrix comprising an interconnected pore structure, wherein a total pore volume of the matrix as determined by mercury porosimetry is greater than or equal to 70% and a bulk density of the matrix is less than or equal to 0.4 g/cm³, and wherein during the firing a majority of the glass beads burst or break.

22. A method of using the substrate of any one of claims 4-5, the method comprising: exposing the substrate to a gas stream including CO2 to adsorb at least some of the CO2 from the gas stream into the coating on the matrix; and desorbing the CO2 from the coating on the matrix, the desorbing comprising applying an electrical potential across the substrate to heat the substrate.