Porous substrate for carrying sorbents or other active materials

Abstract

A porous substrate includes a continuous graphitic phase, and a glass and / or ceramic phase. The graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure. A total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry. The porous substrate is conductive to electricity. A method of forming a porous substrate includes extruding, drying, and firing an extruded extrudable composition that includes a binder and / or sintering aid.

Description

POROUS SUBSTRATE FOR CARRYING SORBENTS OR OTHER ACTIVEMATERIAESCross 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 / 535334, 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 a CO2 laden stream through a monolith containing a sorbent that adsorbs the CO2. The CO2 can later be desorbed for removal (e.g., via heating of the monolith). One convenient way to provide heating of the monolith is via resistive heating; however, conventional conductive monoliths suffer from poor mechanical strength.SUMMARY OF THE INVENTION

[0003] Various aspects of the present disclosure provide a porous substrate that includes a continuous graphitic phase, and a glass and / or ceramic phase. The graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure. A total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry. The porous substrate is conductive to electricity.

[0004] Various aspects of the present disclosure provide a monolithic substrate that includes a continuous graphitic phase, and a glass and / or ceramic phase. The graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure. A total pore volume of the porous substrate is 40% to 95% as determined by mercury porosimetry. The porous substrate also includes a coating on the continuous interconnected pore structure, the coating including an active material, such as a catalyst, a sorbent that adsorbs and desorbs CO2, or a combination thereof. The porous substrates described herein are conductive to electricity.

[0005] In various aspects of the present disclosure, the porous substrate can be an extruded and fired product of an extrudable composition. The extrudable composition includes abinder and / or sintering aid. The extrudable composition can also include graphite particles. The extrudable composition can be an extrudable paste.

[0006] Various aspects of the present disclosure provide a porous substrate that includes an extruded and fired product of an extruded extrudable composition. The extrudable composition includes a binder and / or sintering aid. The extrudable composition also includes graphite particles including graphite plates, graphite flakes, or a combination thereof. The porous substrate includes a continuous graphitic phase, and a glass and / or ceramic phase. The graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure. A total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry. The porous substrate is conductive to electricity.

[0007] In various aspects, the present disclosure provides a method of forming the porous substrate. The method includes extruding the extrudable composition. The method includes drying the extruded composition. The method also includes firing the dried extruded composition, to form the porous substrate.

[0008] In various aspects, the present disclosure provides a method of forming a porous substrate. The method includes extruding an extrudable composition. The extrudable composition includes a binder and / or sintering aid. The extrudable composition also includes graphite particles including graphite plates, graphite flakes, or a combination thereof. The method includes drying the extruded composition. The method also includes firing the extruded composition, to form the porous substrate. The porous substrate includes a continuous graphitic phase, and a glass and / or ceramic phase. The graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure. A total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry. The porous substrate is conductive to electricity.

[0009] In various aspects, the present disclosure provides a method of forming a porous substrate. The method includes extruding an extrudable composition. The extrudable composition includes a binder and / or sintering aid. The extrudable composition includes graphite particles including graphite plates, graphite flakes, or a combination thereof. The extrudable composition also includes hollow glass beads. The method includes drying the extruded composition. The method also includes firing the extruded composition, to form the porous substrate. The firing includes firing the extruded composition in a furnace including an unheated insertion portion, a heated central portion maintained at a temperature of about 920 °C to 1000 °C, and an unheated exit portion. A distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion is a total length of thefurnace (L). The method includes moving the extruded composition through the furnace at a rate that is about 0.01*L per 1 min to 0.1 *L per 1 min, further including holding the extruded composition stationary in the heated central portion for a heating duration that is 5 min to 1 h. The firing is completed in a duration of 20 min to 2 h. The porous substrate includes a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure. A total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry. The porous substrate is conductive to electricity.

[0010] In various aspects, the present disclosure provides a method of forming a porous substrate. The method includes extruding an extrudable composition. The extrudable composition includes a binder and / or sintering aid. The extrudable composition also includes hollow glass beads. The method includes drying the extruded composition. The method also includes firing the extruded composition, to form the porous substrate. The firing includes firing the extruded composition in a furnace. The furnace includes an unheated insertion portion, a heated central portion maintained at a temperature of about 920 °C to 1000 °C, and an unheated exit portion. A distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion is a total length of the furnace (L). The method includes moving the extruded composition through the furnace at a rate that is about 0.01*L per 1 min to 0. 1*L per 1 min, further including holding the extruded composition stationary in the heated central portion for a heating duration that is 5 min to 1 h. The firing is completed in a duration of 20 min to 2 h.

[0011] In various aspects, the present disclosure provides a method of using the porous substrate that includes a coating including a sorbent that adsorbs and desorbs CO2. The method includes exposing the porous substrate to a gas stream including CO2 to at least partially adsorb the CO2 from the gas stream into the coating on the porous substrate. The method also includes desorbing the CO2 from the coating on the porous substrate.

[0012] In various aspects, the porous substrate of the present disclosure has a low thermal mass combined with a high thermal conductivity, providing more efficient heating and cooling than other porous substrates. In various aspects, the porous substrate includes a continuous graphitic phase that is dispersed throughout the ceramic and / or glass phase, providing greater conductivity and increased bonding between the graphite and ceramic / glass phase as compared to porous substrates that include a graphite coating but lack graphite within the ceramic / glass phase. In various aspects of the present disclosure, the porous substrate can include a preferred orientation of graphite particles, which can in variousaspects provide greater electrical and / or thermal conductivity in an extrusion direction than in a direction perpendicular thereto as compared to a corresponding porous substrate having randomly oriented graphite particles or having non-elongated particles that cannot be oriented. In various aspects of the present disclosure, the porous substrate of the present disclosure can have a greater electrical and / or thermal conductivity than other glass / ceramic substrates having a similar low density. In various aspects of the present disclosure, the porous substrate can be conductive, enabling facile and evenly distributed resistive heating (i.e., Joule heating via application of an electrical potential to the porous substrate). In various aspects, the ceramic and / or glass phase provides the porous substrate of the present disclosure with high strength and / or mechanical integrity. In various aspects, the porous substrate of the present disclosure can be easily manufactured by extrusion, drying, and firing of a single extrudable composition including graphite particles as well as sintering aid and / or binder, avoiding extra steps for incorporating the graphitic phase into the porous substrate. In various aspects, the porous substrate of the present disclosure has a combination of high porosity, low mass (e.g., low bulk density), high strength, high electrical conductivity, high thermal conductivity, low cost of operation, low cost of fabrication, and / or facile manufacture, that is not available in other porous substrates.

[0013] Various aspects of the method of forming a porous substrate of the present disclosure provide a faster method of firing (e.g., sintering) an extruded and extrudable composition than other methods. For example, typically compositions including hollow glass beads require more than 10-20 hours to complete firing, while in various embodiments of the method of the present disclosure, the firing can be completed in 2 hours or less, providing a lower cost and higher efficiency method of producing porous substrates. In various aspects of the method of the present disclosure, the produced porous substrate can have the same or similar properties as a porous substrate producing using a conventional 10-20 h firing technique.BRIEF DESCRIPTION OF THE FIGURES

[0014] The drawings illustrate generally, by way of example, but not by way of limitation, various aspects of the present disclosure.

[0015] FIG. 1 illustrates an example substrate having a honeycomb form according to various aspects disclosed herein.

[0016] FIG. 2 illustrates a method of forming a porous substrate according to various aspects disclosed herein.

[0017] FIG. 3A is an SEM image of a portion of a wall of a porous substrate having a honeycomb form comprising a glass and / or ceramic phase and a continuous graphitic phase made according to examples described herein.

[0018] FIG. 3B is an enlarged view of a portion of the SEM image of FIG. 3A.

[0019] FIG. 4 illustrates a temperature profile of the furnace shown in FIG. 1 as temperature versus distance within the furnace from the opening of the insertion portion of the furnace, in accordance with various aspects.

[0020] FIG. 5 is an SEM image of graphite flakes, in accordance with various aspects.DETAILED DESCRIPTION OF THE INVENTION

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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 carriedout in any order without departing from the principles of the disclosure, 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.

[0025] The term “and / or” as used herein means the stated possibilities in the alternative or any combination thereof. For example, “A, B, and / or C” means A, B, C, or a combination thereof.

[0026] 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.

[0027] The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 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 0. 1 wt% of the composition is the material, or about 0 wt% to about 0.01 wt%, or about 0.1 wt% or less, or less than, equal to, or greater than about 0.9 wt%, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.08, 0.06, 0.04, 0.02, 0.01, or about 0.001 wt% or less, or about 0 wt%.Electrically conductive porous substrate.

[0028] Various aspects of the present disclosure provide a porous substrate. 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 phase.

[0029] 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 afluid 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.

[0030] 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.

[0031] The porous substrate can include a continuous graphitic phase. The porous substrate can also include a glass and / or ceramic phase. The graphitic phase and the glass and / or ceramic phase together can form a continuous interconnected pore structure. A total pore volume of the porous substrate can be at least 40% as determined by mercury porosimetry. The porous substrate is conductive to electricity. Mercury porosimetry, such as for determining total pore volume, can be performed as per ASTM D6761-07 (2012).

[0032] The continuity of the graphitic phase in the porous substrate can enable or contribute to the electrically conductive nature of the porous substrate, and the connected and interwoven ceramic and / or glass phase can provide mechanical strength to the porous substrate. By being continuous throughout the porous substrate, the graphitic phase advantageously enables electrical conductivity in both axial and lateral (e.g., radial) directions, which facilitates a variety of electrode attachment orientations. By lateral direction it is meant a direction that is perpendicular to the axial direction, i.e., across opposite sides of the substrate when the substrate is viewed cross-sectionally, such as the radial direction. For example, the continuous graphitic phase enables a pair of electrodes to be connected at or near opposite axial ends, such that electrical current travels axially down the length of the substrate, and / or for the pair of electrodes to be connected at different peripheral sides of the substrate, such that the electrical current travels laterally (e.g., radially) across the substrate in directions transverse to the axial direction. Accordingly, the continuous graphitic phase canenable the electrical current to travel both axially down the length of the substrate and laterally across the substrate.

[0033] In various aspects, the glass and / or ceramic phase can also be a continuous phase in the porous substrate. The graphitic phase, the glass and / or ceramic phase, or both, can be homogeneously distributed in the porous substrate. The continuous graphitic phase can be homogeneously distributed in the glass and / or ceramic phase (e.g., the graphitic phase occurs within and throughout the glass and / or ceramic phase in three dimensions and is not merely a surface coating on the glass and / or ceramic phase).

[0034] The porous substrate can have any suitable bulk density. Bulk density is the mass of the substrate divided by the total volume that the substrate occupies, wherein the total volume the substrate 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 substrate when viewed from a longitudinal end of the substrate that are considered to be open frontal area). The total volume that a substrate with a honeycomb form occupies can be defined as the portions of the substrate when viewed from a longitudinal end of the substrate 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 substrate, while the CFA corresponds to the remaining portions occupied by the matrix of intersecting walls. For example, the porous substrate can have a bulk density of less than 1.5 g / cm3, or in the range of 0.5 g / cm3to 1.15 g / cm3, 0.6 g / cm3to 0.8 g / cm3, or less than or equal to 1.5 g / cm3and greater than or equal to 0.5 g / cm3and less than, equal to, or greater than 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, or l .4 g / cm3. The porous substrate can have any suitable total pore volume (e.g., as measured absent any coating added to the porous substrate), as determined via mercury porosimetry, such as greater than 40%, or in the range of 40% to 95%, 50% to 95%, or less than or equal to 95% and greater than or equal to 40% and less than, equal to, or greater than 42%, 44, 46, 48, 50, 52, 54, 56, 58, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, or 94%.

[0035] The electrically conductive porous substrate can have any suitable electrical resistance, such as an electrical resistance of 1 ohm to 1000 ohms, 1 ohm to 100 ohms, or less than or equal to 1000 ohms and greater than or equal to 1 ohm and less than, equal to, or greater than 2 ohms, 3, 4, 5, 6, 8, 10, 15, 20, 25, 30, 40, 50, 75, 100, 150, 200, 250, 300, 400, 500, 600, 700, 800, 900, or 950 ohms. The electrical resistance can be measured from oneend of the porous substrate to an opposite end, or from one end along a longitudinal axis of the porous substrate to an opposite end along the longitudinal axis.

[0036] The porous substrate can have any suitable physical form. In various aspects, the physical form is that of a honeycomb form, such as 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. 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 shape, as that of a circle, oval, square, rectangle, hexagon, triangle, polygon, or irregular 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 monolith 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. The honeycomb form can have a diameter of 3 inches to 15 inches, or less than or equal to 15 inches and greater than or equal to 3 inches and less than, equal to, or greater than 4 inches, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 inches. The honeycomb form can have a length of 3 inches to 15 inches, or less than or equal to 15 inches and greater than or equal to 3 inches and less than, equal to, or greater than 4 inches, 5, 6, 7, 8, 9, 10, 11, 12, 13. or 14 inches.

[0037] The porous 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 closedfrontal area (or CFA) is the percent cross-sectional (perpendicular to the axial or longitudinal direction) area of the intersecting walls of the substrate (i.e., excluding the open frontal area). For example, the porous substrate can have an open frontal area of 60-90%, 70-80%, or less than 90% and greater than or equal to 60% and less than, equal to, or greater than 61, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, or 89%.

[0038] In embodiments, the graphitic phase comprises one or more carbonaceous materials that result from the manufacture of the porous substrate. For example, graphite particles may be included in a batch mixture with inorganic precursor particles (for forming the glass and / or ceramic phase), then extruded, optionally dried, and fired. Accordingly, at least some of the original graphite particles may be altered during the manufacturing process into one or more other carbonaceous materials. For example, a high temperature sintering process may result in some of the graphite particles transforming into activated carbon, char, or another carbonaceous material. As utilized herein, the term graphitic phase refers to the combination of not only the graphite particles but the other carbonaceous materials, such as activated carbon, char, etc. that are formed with or from the graphite or other batch mixture materials during manufacture of the porous substrate. The graphitic phase can include (a) graphite particles; or (b) an extruded and fired product of (e.g., a sintered product of) graphite particles; or a combination of (a) and (b). The graphitic phase can include (a) graphite plates, graphite flakes, natural graphite, synthetic graphite, or a combination thereof; or (b) an extruded and / or fired product of (e.g., a sintered product of) graphite plates, graphite flakes, natural graphite, synthetic graphite, or a combination thereof; or a combination of (a) and (b). The graphitic phase can include graphite particles that include an elongated morphology and / or a planar shape having a smaller height than a length and width, or the graphitic phase can include an extruded and fired product of such graphite particles, or a combination thereof. A majority (e.g., more than 50%, 60%, 70%, 80%, or more than 90%) of the graphite particles (e.g., in the extruded extrudable composition, the product of the extruded composition, the extruded / fired product of the extrudable composition, or a combination thereof) can have a longitudinal axis and / or an axis orthogonal to the height thereof (e.g., an axis parallel to and passing through a basal plane of a planar shape, such as the basal plane of a graphite plate or graphite flake) oriented in a same direction, such as aligned within 45° of a direction of extrusion, within 30° of a direction of extrusion, or within less than or equal to 45° and greater than or equal to 0° and less than, equal to, or greater than 1°, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 41, 42, 43, or 44° of a direction of extrusion. In various aspects, X-ray diffraction (XRD) can be used to measure a preferredorientation of basal planes of graphite particles, such as by performing XRD of the extruded walls of the porous substrate and comparing an intensity ratio of a 001 plane to a direction perpendicular such as hOO, and then comparing the intensity ratio to a powder mixture having a random orientation of basal planes of the graphite particles.

[0039] In various aspects, the alignment / orientation of the graphite particles in an extrusion direction of the porous substrate can provide the porous substrate with greater electrical conductivity along a cell wall of the substrate than through the cell wall. The electrical conductivity along the cell wall can be 1.1-10 times higher than in a direction through the cell wall, or 3-5 times higher, or less than or equal to 10 times higher and greater than or equal to 1. 1 times higher and less than, equal to, or greater than 1.2, 1.3, 1.4, 1.5, 1.6, 1.8, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, or 9 times higher. Correspondingly, thermal conductivity along the cell wall can be 1.1-10 times higher than through the cell wall, or 3-5 times higher, or less than or equal to 10 times higher and greater than or equal to 1.1 times higher and less than, equal to, or greater than 1.2, 1.3, 1.4, 1.5, 1.6, 1.8, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8, or 9 times higher.

[0040] The graphitic phase can be any suitable proportion of the porous substrate. For example, the graphitic phase can be 2 wt% to 30 wt% of the porous substrate, 5 wt% to 20 wt%, 7 wt% to 19 wt%, or less than or equal to 30 wt% and greater than or equal to 2 wt% and less than, equal to, or greater than 4 wt%, 6, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, or 28 wt%.

[0041] The glass and / or ceramic phase can be any suitable proportion of the porous substrate. For example, the glass and / or ceramic phase can be 10 wt% to 70 wt% of the porous substrate, 15 wt% to 60 wt%, 20 wt% to 55 wt%, or less than or equal to 70 wt% and greater than or equal to 10 wt% and less than, equal to, or greater than 12 wt%, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, or 68 wt%.

[0042] In various aspects the porous substrate can further include a hollow and / or porous material. The hollow and / or porous material can include paper, polymer, glass, glass ceramic, ceramic, diatomaceous earth, or a combination thereof. The hollow and / or porous material can include hollow glass beads. The hollow and / or porous material can form any suitable proportion of the porous substrate, such as 10 wt%to 60 wt% of the porous substrate, or 20 wt% to 50 wt%, or 25 wt% to 45 wt%, or less than or equal to 60 wt% and greater than or equal to 10 wt% and less than, equal to, or greater than 12 wt%, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, or 58 wt%.

[0043] The porous substrate can have any suitable flexural strength in a 4-point bend test of the porous substrate, such as performed per ASTM-D6272. For ease of comparison ofhoneycomb monoliths having different geometries, the strength can be normalized by CFA of the porous substrate. For example, the porous substrate can have a flexural strength in a 4- point bend test of the porous substrate normalized by CFA of the porous substrate (i.e., divided by the CFA of the porous substrate, given as a percentage) of greater than 500 psi, or in the range of 500 psi to 2500 psi, or 1000 psi to 2500 psi, or less than or equal to 3000 psi and greater than or equal to 500 psi and less than, equal to, or greater than 600 psi, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, or 2400 psi.

[0044] Cristobalite can be 30 wt% or less of the porous substrate, or 10 wt% or less of the porous substrate, such as 0 wt% to 29 wt%, or 0 wt% to 9.9 wt%, or less than or equal to 29 wt% and greater than or equal to 0 wt% and less than, equal to, or greater than 0.5 wt%, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, or 28 wt%.

[0045] The porous substrate can optionally include a coating. The coating can include any suitable material, such as a sorbent (e.g., a sorbent that adsorbs and desorbs CO2), a catalyst (e.g., a catalyst for treating exhaust emissions in a catalytic converter, or another catalyst), or some other active or functional material that participates in the capture, trapping, adsorption, absorption, reaction, treatment, abatement, or conversion of one or more selected compounds, such as a pollutant to be removed or a compound to be harvested. Many materials may require a certain temperature before they become active. For example, some catalysts may only function above a threshold “light-off’ temperature, while some sorbents may require a certain temperature before carbon dioxide is desorbed in a carbon capture cycle.Advantageously, the electrically conductive nature of the porous substrates described herein enable the temperature of the substrates to be directly controlled by passing an electrical current through the substrates, which enables a catalyst, sorbent, or other temperaturedependent active material to be effectively controlled.

[0046] In various aspects, the coating can be directly adhered to the porous substrate, wherein the porous substrate is free of an intervening bonding layer between the coating and the glass and / or ceramic phase. However, in various aspects, the porous substrate can include a bonding layer. 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. A 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 porous 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 porous 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%.

[0047] The porous substrate can be an extruded and fired product of an extrudable composition. The extrudable composition, which can alternatively be referred to as a batch, batch mixture, or batch composition, can include a binder and / or sintering aid. The extrudable composition can also include graphite particles. The extrudable composition can be an extrudable paste comprising the foregoing ingredients combined with a liquid component, such as water, in addition to oils, fatty acids, or other extrusion aids or lubricants

[0048] The binder and / or sintering aid can be any suitable proportion of the extrudable composition. For example, based on a dry weight of the extrudable composition, the binder and / or sintering aid can be 10 wt% to 70 wt% of the extrudable composition, or 15 wt% to 60 wt%, or 20 wt% to 55 wt%, or less than or equal to 70 wt% and greater than or equal to 10 wt% or less than, equal to, or greater than 12 wt%, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, or 68 wt%. The binder and / or sintering aid can include an inorganic binder, a polymer, a thermosetting resin, a carbon precursor, a borate, a phosphate, a transition metal oxide, an oxide, a hydroxide, a carbonate, a silicate, an alumino-silicate, a cellulose derivative, 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.

[0049] The graphite particles can include graphite plates, graphite flakes, natural graphite, synthetic graphite, or a combination thereof. The graphite particles can include an elongated morphology and / or a planar shape having a smaller height than a length and width. The graphite particles can have a median longest dimension (e.g., diameter) of 1 micron to 100 microns, 5 microns to 15 microns, or less than or equal to 1 microns and greater than or equal to 100 microns or less than, equal to, or greater than 2 microns, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 35, 40, 45, 50, 60, 70, 80, or 90 microns.The graphite particles can have an aspect ratio (e.g., thickness to diameter) of 1:2 to 1: 100, or 1 :5 to 1 : 15, or less than or equal to 1:2 and greater than or equal to 1 : 100 and less than, equal to, or greater than 1:3, 1:4, 1:5, 1:6, 1:7, 1 :8, 1:9, 1: 10, 1: 11, 1: 12, 1 : 13, 1: 14, 1: 15, 1: 16, 1: 17, 1: 18, 1: 19, 1:20, 1:25, 1:30, 1:35, 1:40, 1 :45, 1:50, 1:60, 1:70, 1:80, or 1:90. The graphite particles can be any suitable proportion of the extrudable composition. For example, on a dry weight basis, the graphite particles can be 2 wt% to 30 wt% of the extrudable composition, 5 wt% to 20 wt%, 7 wt% to 19 wt%, or less than or equal to 30 wt% and greater than or equal to 2 wt% or less than, equal to, or greater than 4 wt%, 6, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, or 28 wt%.

[0050] The extrudable composition can further include one or more solvents, such as an aqueous solvent or an organic solvent. The solvent can be or include water. The solvent can form any suitable proportion of the extrudable composition, such as 5 wt% to 60 wt%, or 10 wt% to 40 wt%, or less than or equal to 60 wt% and greater than or equal to 5 wt% and less than, equal to, or greater than 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 wt%.

[0051] 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%.

[0052] In various aspects, the extrudable composition can further include a hollow and / or porous material. The hollow and / or porous material can include paper, polymer, glass, glass ceramic, ceramic, diatomaceous earth, or a combination thereof. The hollow and / or porous material can include hollow glass beads. The hollow and / or porous material can be any suitable proportion of the extrudable composition. For example, on a dry weight basis, the hollow and / or porous material can be 10 wt% to 60 wt% of the extrudable composition, 20 wt% to 50 wt%, 25 wt% to 45 wt%, or less than or equal to 60 wt% and greater than or equal to 10 wt% or less than, equal to, or greater than 12 wt%, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, or 58 wt%.

[0053] In various aspects, the extrudable composition further includes a pore-forming material, wherein the pore-forming material degrades and / or pyrolyzes (e.g., bums out) during firing to form pores in the porous substrate. The pore-forming material can be anysuitable pore-forming material, such as a starch (e.g., a cross-linked starch, such as crosslinked pea starch), a nut-shell flour, carbon, a natural polymer, a synthetic polymer, a carbonaceous material, crystalline carbon, amorphous carbon, or a combination thereof. The pore-forming material can be any suitable proportion of the extrudable composition. For example, on a dry weight basis, the pore-forming material can be 5 wt% to 50 wt% of the extrudable composition, 10 wt% to 30 wt%, 14 wt% to 27 wt%, or less than or equal to 50 wt% and greater than or equal to 5 wt% or less than, equal to, or greater than 6 wt%, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, or 48 wt%.Method of forming a conductive porous substrate.

[0054] Various aspects of the present disclosure provide a method of forming the electrically conductive porous substrate described herein. One example is illustrated in FIG. 2. In this example, the method includes extruding an extrudable composition 10, which may be alternatively referred to as a batch or batch mixture, via an extruder 20. For example, the extruder 20 may comprise a honeycomb extrusion die to shape the extrudable composition 10 into a honeycomb form. Accordingly, in the example of FIG. 2, the extruded body is provided with the reference number 100G indicating that this is the substrate 100 in its green (fired) state. The method optionally includes drying the extruded composition (e.g., the green, unfired substrate 100G). The method also includes firing the extruded composition (e.g., the green, unfired substrate 100G) via a furnace (or kiln) 30, to form the porous substrate 100.

[0055] The optional drying step can be any suitable drying that substantially removes solvent from the extruded composition. The drying can include heating, air flow, and / or exposing to microwaves or other energy sources. The drying can include placing the extruded composition under a vacuum. The drying can include drying at a sufficient temperature and for a sufficient duration to substantially remove all solvent from the extruded composition (e.g., such that the dried composition has a solvent content less than 5 wt%, or less than 2 wt%, less than 1 wt%, less than 0.5 wt%, or less than 0. 1 wt%).

[0056] The firing can include firing at a firing soak temperature of 600 °C to 1100 °C, or 650 °C to 950 °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 650 °C, 700, 750, 800, 850, 900, 950, 1000, or 1050 °C. The firing soak temperature can be sufficient to cause reaction and / or sintering of the binder and / or sintering aid. The firing can include firing for a duration of (e.g., maintaining the firing soak temperature for a duration of) 1 h to 24 h, 2 h to 6 h, or less than or equal to 24 hand greater than or equal to 1 h and less than, equal to, or greater than 2 h, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, or 22 h. The firing can include ramping a temperature of the extruded composition up to a firing soak temperature at a rate of 10 °C / h to 100 °C / h, or 30 °C / h to 70 °C / h, or less than or equal to 100 °C / h and greater than or equal to 10 °C / h and less than, equal to, or greater than 20 °C, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95 °C. The firing can include firing in an atmosphere including an oxygen concentration that is sufficiently low to prevent oxidation of the graphene particles during the firing. For example, the firing can be conducted under an inert gas, such as nitrogen or argon. The firing can be conducted in the presence of a material that absorbs oxygen, such as an oxygen getter. By limiting the amount of oxygen during the firing, oxidation of the graphite particles can be reduced or eliminated.

[0057] As compared to the extruded composition, the porous substrate can have a shrinkage of 0% to 15%, 2% to 7%, or less than or equal to 15% and greater than or equal to 0% and less than, equal to, or greater than 1%, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14%. The shrinkage can be a change in diameter from the extruded product to the final fired product (e.g., linear shrinkage).

[0058] The firing can include firing the extruded composition in any suitable type of furnace (kiln) having any suitable temperature profile. In various aspects, the firing can include firing the extruded composition in a furnace that includes an unheated insertion portion. The furnace can include a heated central portion maintained at a temperature of about 920 °C to 1000 °C, about 930 °C to about 970 °C, or less than or equal to 1000 °C and greater than or equal to 920 °C and less than, equal to, or greater than 925 °C, 930, 935, 940, 945, 950, 955, 960, 965, 970, 975, 980, 985, 990, or 995 °C. The furnace can also include an unheated exit portion. The method can include maintaining the extruded composition at a preheat distance from the entrance to the furnace, or from the entrance to the unheated insertion portion, for a preheat duration before inserting the extruded composition into the furnace. The preheat distance can be 0.01 m to 0. 1 m, or less than or equal to 0.1 m and greater than or equal to 0.01 m and less than, equal to, or greater than 0.02 m, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, or 0.09 m. The preheat duration can be 1 min to 10 min, or less than or equal to 10 min and greater than or equal to 1 min and less than, equal to, or greater than 2 min, 3, 4, 5, 6, 7, 8, or 9 min. A distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion can be a total length of the furnace (L), wherein the method includes moving the extruded composition through the furnace at a rate that is about 0.01*L per 1 min to 0. 1*L per 1 min, further including holding the extruded composition stationary in theheated central portion for a heating duration that is 5 min to 1 h. The rate can be 0.01*L per 1 min to 0.1 *L per 1 min, or 0.03*L to 0.07*L, or less than or equal to 0.1 *L per 1 min and greater than or equal to 0.01*L per 1 min and less than, equal to, or greater than 0.02*L per 1 min, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, or 0.09*L per 1 min. The heating duration can be 5 min to 1 h, or 10 min to 30 min, or less than or equal to 1 h and greater than or equal to 5 min and less than, equal to, or greater than 10 min, 15, 20, 25, 30, 35, 40, 45, 50, or 55 min. The firing can be completed in a duration of 20 min to 2 h, or 30 min to 1 h, or less than or equal to 2 h and greater than or equal to 20 min and less than, equal to, or greater than 30 min, 40, 50, 60, 70, 80, 90, 100, or 110 min. The extrudable composition can include hollow glass beads.Method of forming a porous substrate in a furnace including insertion portion, central portion, and exit portion.

[0059] Various aspects of the present disclosure provide a method of forming a porous substrate. The porous substrate can be the electrically conductive porous substrate of the present disclosure described herein, or another porous substrate (e.g., an electrically non- conductive porous substrate). The method can include extruding an extrudable composition including a binder and / or sintering aid. The method can include drying the extruded composition. The method can also include firing the extruded composition, to form the porous substrate. The firing can include firing the extruded composition in a furnace that includes an unheated insertion portion. The furnace can include a heated central portion maintained at a temperature of about 920 °C to 1000 °C, about 930 °C to about 970 °C, or less than or equal to 1000 °C and greater than or equal to 920 °C and less than, equal to, or greater than 925 °C, 930, 935, 940, 945, 950, 955, 960, 965, 970, 975, 980, 985, 990, or 995 °C. The furnace can also include an unheated exit portion. The method can include maintaining the extruded composition at a preheat distance from the entrance to the furnace, or from the entrance to the unheated insertion portion, for a preheat duration before inserting the extruded composition into the furnace. The preheat distance can be 0.01 m to 0. 1 m, or less than or equal to 0. 1 m and greater than or equal to 0.01 m and less than, equal to, or greater than 0.02 m, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, or 0.09 m. The preheat duration can be 1 min to 10 min, or less than or equal to 10 min and greater than or equal to 1 min and less than, equal to, or greater than 2 min, 3, 4, 5, 6, 7, 8, or 9 min. A distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion can be a total length of the furnace (L), wherein the method includes moving the extruded composition through thefurnace at a rate that is about 0.01*L per 1 min to 0. 1*L per 1 min, further including holding the extruded composition stationary in the heated central portion for a heating duration that is 5 min to 1 h. The rate can be 0.01*L per 1 min to 0.1*L per 1 min, or 0.03*L to 0.07*L, or less than or equal to 0. 1*L per 1 min and greater than or equal to 0.01*L per 1 min and less than, equal to, or greater than 0.02*L per 1 min, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, or 0.09*L per 1 min. The heating duration can be 5 min to 1 h, or 10 min to 30 min, or less than or equal to 1 h and greater than or equal to 5 min and less than, equal to, or greater than 10 min, 15, 20, 25, 30, 35, 40, 45, 50, or 55 min. The firing can be completed in a duration of 20 min to 2 h, or 30 min to 1 h, or less than or equal to 2 h and greater than or equal to 20 min and less than, equal to, or greater than 30 min, 40, 50, 60, 70, 80, 90, 100, or 110 min. The extrudable composition can include hollow glass beads.Method of using a porous substrate.

[0060] Various aspects of the present disclosure provide a method of using the electrically conductive porous substrate of the present disclosure that includes a coating thereon that includes a sorbent that can adsorb and desorb CO2. The coating can be continuous or discontinuous. The method can include exposing the porous substrate to a gas stream that includes CO2 to at least partially adsorb the CO2 from the gas stream. The method can also include desorbing the CO2 from the coating on the porous substrate. In various aspects, desorbing the CO2 from the coating on the porous substrate includes heating the porous substrate, such as via resistive heating, sending hot gas (e.g., steam) through the porous substrate, microwave heating, induction heating, via an external heat source at a periphery of the porous substrate, or a combination thereof. In various aspects, desorbing the CO2 from the coating can include sequestering the CO2, such as placing the CO2 in a storage tank.

[0061] The methods of using the porous 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. The porous substrate described herein can be capable of withstanding temperatures of 200 °C or more and withstanding moist environments.

[0062] Various aspects of the present disclosure provide a method of using the electrically conductive porous substrate of the present disclosure that includes a coating thereon that includes a catalyst. The method can include exposing the porous substrate to a gas stream to catalyze a chemical reaction of one or more components of the gas stream using the catalyst.Examples

[0063] 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. Mercury porosimetry was performed as per ASTM D6761-07 (2012). The monoliths may be referred to in the description of the Examples interchangeably as monoliths, parts, or samples.

[0064] SEM images of a representative example substrate having a glass and / or ceramic phase and a continuous graphitic phase are illustrated in FIGS. 3A and 3B. In particular, the substrate in FIG. 3A and 3B was made from a mixture comprising hollow glass microspheres (HGMS), clay, talc, starch pore former, and graphite powder, which was extruded into a honeycomb shape and fired. In FIGS. 3A and 3B the portions of the structure resulting from the HGMS particles can be identified as circular or ring-shaped areas of white, one such area is labeled with reference number 110. In contrast, the similarly sized large black and dark gray circular or oval areas, one of which is labeled with reference number 114, indicate pores (voids) and char left behind from starch pore former particles that were burned out or combusted during firing. The relatively smaller size of the talc, clay, and graphite particles that were utilized resulted in these materials conglomerating into the interstitial spaces between the HGMS particles and the pore former particles (before combustion during firing), which is indicated with the reference number 112. In this way, the inorganic particles (e.g., talc, clay, HGMS) sintered together and / or at least partially reacted into one or more ceramic phases to create the glass and / or ceramic phase, which serves as a “backbone” for the substrate, while the graphite particles, together with any remaining char resulting from sintering, create a continuous graphitic phase that imparts electrical conductivity to the substrate as described herein.Examples 1-33,

[0065] The inorganics for each of the compositions shown in Tables 1-3 were dry mixed in a Littleford mixer, followed by addition of water and MOx 30A (mineral oil) with an additional wet mix cycle. The wet powder was then transferred into a 40 mm twin screw mixer and extruded through 2” diameter dies of either 200 cells per square in (cpsi) / 8 mil slots or 300 cpsi and 8 mil slots. The parts were dried in a microwave dryer and fired in a gas kiln to temperatures between 650 °C and 950 °C for 4 hours in covered crucibles, as also indicated in Tables 1-3. A green cookie was placed on top of the parts in the crucibles to act as anoxygen geter for any air that leaked between the crucible and lid. This method of firing protected the graphite from oxidation during firing.

[0066] Compositions and physical properties are shown in Table 1-3. The first row shows the Example number. The second row indicates whether the Example is inventive or comparative. The following set of rows show the inorganic raw materials used and the level used in wt%. ZH C70 HGMS is hollow glass microspheres. Diafil 525 is a type of diatomaceous earth. The graphite was graphite flakes having a median particle diameter of 9 microns and having an aspect ratio of about 8-12: 1. FIG. 5 illustrates an SEM image of the graphite flakes. Kaolin clay and platy talc particles were also used in some examples. Potassium carbonate (K2CO3) and boric acid were also used as sintering aids as summarized in the Tables.

[0067] The organic materials and water used are shown next and the amounts used are given in terms of superadditions to 100 parts inorganics. The pea starch is crosslinked pea starch.

[0068] Tables 1-3 show the firing soak temperature. Each composition was heated at a rate of 50°C / hr to the soak temperature where it was held for 4 hours. Shrinkage is given as an average shrinkage in diameter from the extrusion mask to the fired part. It is desirable that the shrinkage be less than about 10% to maintain good dimensional control through the process. The geometry is given as a nominal cell density (cells / in2or cpsi) and web thickness in mils. Bulk density of the porous material (independent of the channels of the honeycomb structure) was measured by mercury porosimetry. Porosity is a vol% determined by mercury porosimetry. The median pore diameter (of the entire pore size distribution) is given in microns as determined by mercury porosimetry. Modulus of rupture (MOR) was measured by a 4-point bend test of a rectangular bar cut out of the fired parts, as per ASTM-D6272. MOR was normalized by the CFA to eliminate influence of cell geometry. Cristobalite concentration was measured by a Rietveld XRD analysis of the fired part. Cristobalite is a high thermal expansion material which also has volume change associated with a phase change at about 200°C. It has been found that concentrations above about 10% can result in cracking of the fired parts upon cooling from soak and so it is desirable to minimize the concentration of this phase in the fired product. Finally, the last row shows whether the product has a resistance suitable for supporting resistive heating and good thermal conductivity. Table 4 is the same as Table 1, Table 5 is the same as Table 2, and Table 6 is the same as Table 3, except in Tables 3-6, the amounts of materials are given in terms of wt% of the composition on a dry basis, and also Tables 3-6 omit the firing conditions and physical properties of the resulting substrates.

[0069] Table 1. Compositions fired, firing conditions, and physical properties of resulting substrates, with organic materials and water given in terms of superadditions to 100 parts inorganics.

[0070] Table 2. Compositions fired, firing conditions, and physical properties of resulting substrates, with organic materials and water given in terms of superadditions to 100 parts inorganics.

[0071] Table 3. Compositions fired, firing conditions, and physical properties of resulting substrates, with organic materials and water given in terms of superadditions to 100 parts inorganics.

[0072] Table 4. Compositions fired, firing conditions, and physical properties of resulting substrates.

[0073] Table 5. Compositions fired, firing conditions, and physical properties of resulting substrates.

[0074] Table 6. Compositions fired, firing conditions, and physical properties of resulting substrates.

[0075] The compositions fired in Examples 1 and 2 were mixtures of HGMS and graphite. Although the resulting substrates showed good conductivity, it can be seen that they suffered from poor strength. The compositions fired in Examples 3-21 and 25-33 included added (CSG) along with boric acid and potassium carbonate as sintering aids. It can be seen that these composition modifications led to considerable gains in strength while maintaining good conductivity. Of particular interest are Examples 3 through 15 which had low cristobalite content and reasonable strength when fired at lower temperatures. Examples 19 through 27 meet most of the inventive criteria but resistance was higher than desired for these compositions. To improve in that category, the graphite content was increased in Examples 28-33, which are currently undergoing testing / characterization.Example 34, Fast sintering.

[0076] All sintering in this Example is performed under a nitrogen atmosphere.

[0077] The first sintering technique included heating an extruded dried substrate in a box furnace from ambient temperature to 900 °C at a ramp rate of 400 °C / h, holding for two hours at 900 °C, and then allowing to cool to ambient temperature at a rate of -400 °C / h. The first sintering technique was designed for about seven hours, but lasted for more than 10 hours due to slow cooling without forced cooling. Even with more efficient cooling, the first sintering technique required about 7 hours.

[0078] In the second sintering technique, a tubular furnace was used that included an unheated insertion portion, a heated central portion, and an unheated exit portion. Each portion was 14” long. The total length of the furnace was 42”. Samples were loaded into the insertion portion via a wire that ran longitudinally through the furnace that included a vehicle thereon for carrying the sample. The insertion portion had an open end for inserting the samples, and the exit portion was sealed with a central hole for removing samples. The wire was driven by a motor. In the fast sintering technique, the tube furnace is preheated to 950 °C (in the central portion). FIG. 4 illustrates a temperature profile of the furnace from the open end to the beginning of the heated central portion. Samples were held at 2” from open end for 3 minutes, which helped slow down organic binder burning out to avoid cracking. The sample was then carried to center of the furnace at 2” per minute; held 20 minutes at center of the furnace; and then carried out at 2” per minute. The cycle took a total of 44 minutes.

[0079] Table 7 illustrates the two extruded compositions that were each fired using the first sintering technique and the second sintering technique.

[0080] Table 7, Extrudable compositions of Example 2

[0081] The two extruded compositions were 1” square honeycomb with a cell density of 300 per square inch and a wall thickness of 8 mil cut to 1” length. The properties of the two extruded compositions are shown in Table 8, which shows that all measured properties including porosity, pore size, bulk density, and resistance were very close for both the first sintering technique and the second sintering technique.

[0082] Table 8. Properties of fired porous substrates compositions of Example 2.

[0083] 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 includes 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.

[0084] The following exemplary aspects are provided, the numbering of which is not to be construed as designating levels of importance:

[0085] Aspect 1 provides a porous substrate comprising: a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure, wherein a total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry; wherein the porous substrate is conductive to electricity.

[0086] Aspect 2 provides the porous substrate of Aspect 1, wherein the glass and / or ceramic phase is a continuous phase.

[0087] Aspect 3 provides the porous substrate of any one of Aspects 1-2, wherein the continuous graphitic phase is homogeneously distributed in the glass and / or ceramic phase.

[0088] Aspect 4 provides the porous substrate of any one of Aspects 1-3, wherein the total pore volume of the porous substrate is 40% to 95% as determined by mercury porosimetry.

[0089] Aspect 5 provides the porous substrate of any one of Aspects 1-4, wherein the total pore volume of the porous substrate is 50% to 95% as determined by mercury porosimetry.

[0090] Aspect 6 provides the porous substrate of any one of Aspects 1-5, wherein the porous substrate has an electrical resistance of 1 ohm to 1,000 ohms.

[0091] Aspect 7 provides the porous substrate of any one of Aspects 1-6, wherein the porous substrate has an electrical resistance of 1 ohm to 100 ohms.

[0092] Aspect 8 provides the porous substrate of any one of Aspects 1-7, wherein the porous substrate has a cell density of 20 cells per square inch to 1,000 cells per square inch.

[0093] Aspect 9 provides the porous substrate of any one of Aspects 1-8, wherein the porous substrate has a wall thickness of 0.002 inches to 0.05 inches.

[0094] Aspect 10 provides the porous substrate of any one of Aspects 1-9, wherein the porous substrate has a bulk density of less than 1.5 g / cm3.

[0095] Aspect 11 provides the porous substrate of any one of Aspects 1-10, wherein the porous substrate has a bulk density of 0.5 g / cm3to 1.15 g / cm3.

[0096] Aspect 12 provides the porous substrate of any one of Aspects 1-11, wherein the porous substrate has a bulk density of 0.6 g / cm3to 0.8 g / cm3.

[0097] Aspect 13 provides the porous substrate of any one of Aspects 1-12, wherein the porous substrate has a closed frontal area of 10% to 40%.

[0098] Aspect 14 provides the porous substrate of any one of Aspects 1-13, wherein the porous substrate has a closed frontal area of 20% to 30%.

[0099] Aspect 15 provides the porous substrate of any one of Aspects 1-14, wherein the graphitic phase is distributed homogeneously throughout the continuous interconnected pore structure.

[0100] Aspect 16 provides the porous substrate of any one of Aspects 1-15, wherein the graphitic phase comprises graphite plates, graphite flakes, natural graphite, synthetic graphite, or a combination thereof; or an extruded and fired product of graphite plates, graphite flakes, natural graphite, synthetic graphite, or a combination thereof; or a combination thereof.

[0101] Aspect 17 provides the porous substrate of any one of Aspects 1-16, wherein the graphitic phase comprises graphite particles that comprise an elongated morphology.

[0102] Aspect 18 provides the porous substrate of Aspect 17, wherein a majority of the graphite particles have a longitudinal axis and / or an axis orthogonal to the height thereof oriented in a same direction

[0103] Aspect 19 provides the porous substrate of any one of Aspects 17-18, wherein the porous substrate is an extruded product of an extrudable composition, wherein the majority of the graphite particles have a longitudinal axis and / or an axis orthogonal to the height thereof oriented within 45° to a direction of extrusion.

[0104] Aspect 20 provides the porous substrate of any one of Aspects 17-19, wherein the porous substrate is an extruded product of an extrudable composition, wherein the majority of the graphite particles have a longitudinal axis and / or an axis orthogonal to the height thereof oriented within 30° to a direction of extrusion.

[0105] Aspect 21 provides the porous substrate of any one of Aspects 1-20, wherein the porous substrate is an extruded product of an extrudable composition, wherein the porous substrate has a greater electrical conductivity along a cell wall as compared to an electrical conductivity through the cell wall.

[0106] Aspect 22 provides the porous substrate of any one of Aspects 1-21, wherein the graphitic phase is 2 wt% to 30 wt% of the porous substrate.

[0107] Aspect 23 provides the porous substrate of any one of Aspects 1-22, wherein the graphitic phase is 5 wt% to 20 wt% of the porous substrate.

[0108] Aspect 24 provides the porous substrate of any one of Aspects 1-23, wherein the glass and / or ceramic phase is 10 wt% to 70 wt% of the porous substrate.

[0109] Aspect 25 provides the porous substrate of any one of Aspects 1-24, wherein the glass and / or ceramic phase is 15 wt% to 60 wt% of the porous substrate.

[0110] Aspect 26 provides the porous substrate of any one of Aspects 1-25, further comprising a hollow and / or porous material comprising paper, polymer, glass, glass ceramic, ceramic, diatomaceous earth, or a combination thereof.

[0111] Aspect 27 provides the porous substrate of Aspect 26, wherein the hollow and / or porous material comprises hollow glass beads.

[0112] Aspect 28 provides the porous substrate of any one of Aspects 26-27, wherein the hollow and / or porous material is 10 wt% to 60 wt% of the porous substrate.

[0113] Aspect 29 provides the porous substrate of any one of Aspects 26-28, wherein the hollow and / or porous material is 20 wt% to 45 wt% of the porous substrate.

[0114] Aspect 30 provides the porous substrate of any one of Aspects 1-29, wherein flexural strength in a 4-point bend test of the porous substrate normalized by CFA of the porous substrate is greater than 500 psi.

[0115] Aspect 31 provides the porous substrate of any one of Aspects 1-30, wherein flexural strength in a 4-point bend test of the porous substrate normalized by CFA of the porous substrate is 500 psi to 2,500 psi.

[0116] Aspect 32 provides the porous substrate of any one of Aspects 1-31, wherein flexural strength in a 4-point bend test of the porous substrate normalized by CFA of the porous substrate is 1,000 psi to 2,500 psi.

[0117] Aspect 33 provides the porous substrate of any one of Aspects 1-32, wherein cristobalite is 10 wt% or less of the porous substrate.

[0118] Aspect 34 provides the porous substrate of any one of Aspects 1-33, wherein the porous 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.

[0119] Aspect 35 provides the porous substrate of Aspect 34, wherein the honeycomb form has a circumferential profde of a circle, oval, square, rectangle, hexagon, triangle, polygon, or irregular shape.

[0120] Aspect 36 provides the porous substrate of any one of Aspects 34-35, wherein cells of the honeycomb have a profde a circle, oval, square, rectangle, hexagon, triangle, polygon, or irregular shape, when viewed from an end of the honeycomb form.

[0121] Aspect 37 provides the porous substrate of any one of Aspects 1-36, wherein the porous substrate comprises a coating thereon, the coating comprising a catalyst, a sorbent that adsorbs and desorbs CO2, or a combination thereof.

[0122] Aspect 38 provides the porous substrate of Aspect 37, wherein the sorbent comprises a zeolite, sodium carbonate, activated carbon, carbon nanotubes, a metal-organic framework (MOF), an amine, or a combination thereof.

[0123] Aspect 39 provides the porous substrate of any one of Aspects 37-38, wherein the coating is directly adhered to the continuous interconnected pore structure, wherein the porous substrate is free of an intervening layer between the coating and the glass and / or ceramic phase.

[0124] Aspect 40 provides the porous substrate of any one of Aspects 37-38, wherein the porous substrate comprises a washcoat between the continuous interconnected pore structure and the coating that comprises the sorbent.

[0125] Aspect 41 provides the method of Aspect 40, wherein the washcoat comprises gamma alumina, zeolite, activated carbon, or a combination thereof.

[0126] Aspect 42 provides the method of any one of Aspects 40-41, wherein the washcoat comprises gamma alumina.

[0127] Aspect 43 provides a porous substrate comprising: a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure, wherein a total pore volume of the porous substrate is 40% to 95% as determined by mercury porosimetry; and a coating on the continuous interconnected pore structure, the coating comprising a catalyst, a sorbent that adsorbs and desorbs CO2, or a combination thereof; wherein the porous substrate is conductive to electricity.

[0128] Aspect 44 provides the porous substrate of any one of Aspects 1-43, wherein the porous substrate is an extruded and fired product of an extrudable composition, the extrudable composition comprising: a binder and / or sintering aid; and graphite particles.

[0129] Aspect 45 provides the porous substrate of Aspect 44, wherein the binder and / or sintering aid is 10 wt% to 70 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0130] Aspect 46 provides the porous substrate of any one of Aspects 44-45, wherein the binder and / or sintering aid is 15 wt% to 60 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0131] Aspect 47 provides the porous substrate of any one of Aspects 44-46, wherein the binder and / or sintering aid comprises an inorganic binder, a polymer, a thermosetting resin, a carbon precursor, a borate, a phosphate, a transition metal oxide, an oxide, a hydroxide, a carbonate, a silicate, an alumino-silicate, or a combination thereof.

[0132] Aspect 48 provides the porous substrate of any one of Aspects 44-47, wherein the graphite particles are 2 wt% to 30 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0133] Aspect 49 provides the porous substrate of any one of Aspects 44-48, wherein the graphite particles are 5 wt% to 20 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0134] Aspect 50 provides the porous substrate of any one of Aspects 44-49, wherein the graphite particles are graphite plates, graphite flakes, or a combination thereof.

[0135] Aspect 51 provides the porous substrate of any one of Aspects 44-50, wherein the graphite particles have a median longest dimension of 1 micron to 100 microns.

[0136] Aspect 52 provides the porous substrate of any one of Aspects 44-51, wherein the graphite particles have a median longest dimension of 5 microns to 15 microns.

[0137] Aspect 53 provides the porous substrate of any one of Aspects 44-52, wherein the extrudable composition further comprises one or more solvents.

[0138] Aspect 54 provides the porous substrate of any one of Aspects 44-53, wherein the extrudable composition further comprises a hollow and / or porous material comprising paper, polymer, glass, glass ceramic, ceramic, diatomaceous earth, or a combination thereof.

[0139] Aspect 55 provides the porous substrate of Aspect 54, wherein the hollow and / or porous material comprises hollow glass beads.

[0140] Aspect 56 provides the porous substrate of any one of Aspects 54-55, wherein the hollow and / or porous material is 10 wt% to 60 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0141] Aspect 57 provides the porous substrate of any one of Aspects 54-56, wherein the hollow and / or porous material is 20 wt% to 50 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0142] Aspect 58 provides the porous substrate of any one of Aspects 44-57, wherein the extrudable composition further comprises a pore-forming material.

[0143] Aspect 59 provides the porous substrate of Aspect 58, wherein the pore-forming material comprises a starch, a nut-shell flour, carbon, a natural polymer, a synthetic polymer, a carbonaceous material, crystalline carbon, amorphous carbon, or a combination thereof.

[0144] Aspect 60 provides the porous substrate of any one of Aspects 58-59, wherein the pore-forming material is 5 wt% to 50 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0145] Aspect 61 provides the porous substrate of any one of Aspects 58-60, wherein the pore-forming material is 10 wt% to 30 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

[0146] Aspect 62 provides a porous substrate comprising: an extruded and fired product of an extruded extrudable composition, the extrudable composition comprising a binder and / or sintering aid, andgraphite particles comprising graphite plates, graphite flakes, or a combination thereof; wherein the porous substrate comprises a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure, wherein a total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry; wherein the porous substrate is conductive to electricity.

[0147] Aspect 63 provides a method of forming the porous substrate of any one of Aspects 44-62, the method comprising: extruding the extrudable composition; drying the extruded composition; and firing the dried extruded composition, to form the porous substrate.

[0148] Aspect 64 provides the method of Aspect 63, wherein the drying comprises heating and / or exposing to microwaves.

[0149] Aspect 65 provides the method of any one of Aspects 63-64, wherein the drying comprises placing the extruded composition under a vacuum.

[0150] Aspect 66 provides the method of any one of Aspects 63-65, wherein the drying comprising drying at a sufficient temperature and for a sufficient duration to substantially remove all solvent in the extruded composition.

[0151] Aspect 67 provides the method of any one of Aspects 63-66, wherein the firing comprises firing at a firing soak temperature of 600 °C to 1100 °C.

[0152] Aspect 68 provides the method of any one of Aspects 63-67, wherein the firing comprises firing at a firing soak temperature of 650 °C to 950 °C.

[0153] Aspect 69 provides the method of any one of Aspects 63-68, wherein the firing comprises firing for a duration of 1 h to 24 h.

[0154] Aspect 70 provides the method of any one of Aspects 63-69, wherein the firing comprises firing for a duration of 2 h to 6 h.

[0155] Aspect 71 provides the method of any one of Aspects 63-70, wherein the method comprises ramping a temperature of the dried extruded composition up to a firing soak temperature at a rate of 10 °C / h to 100 °C / h.

[0156] Aspect 72 provides the method of any one of Aspects 63-71, wherein the method comprises ramping a temperature of the dried extruded composition up to a firing soak temperature at a rate of 30 °C / h to 70 °C / h.

[0157] Aspect 73 provides the method of any one of Aspects 63-72, wherein the firing comprising firing in an atmosphere comprising an oxygen concentration that is sufficiently low to prevent oxidation of the graphene particles during the firing.

[0158] Aspect 74 provides the method of any one of Aspects 63-73, wherein the firing is conducted under an insert gas.

[0159] Aspect 75 provides the method of any one of Aspects 63-74, wherein as compared to the extruded composition, the porous substrate has a shrinkage of 0% to 15%.

[0160] Aspect 76 provides the method of any one of Aspects 63-75, wherein as compared to the extruded composition, the porous substrate has a shrinkage of 2% to 7%.

[0161] Aspect 77 provides the method of any one of Aspects 63-76, wherein the firing comprises firing the dried extruded composition in a furnace comprising an unheated insertion portion, a heated central portion maintained at a temperature of about 920 °C to 1000 °C, and an unheated exit portion.

[0162] Aspect 78 provides the method of Aspect 77, wherein the heated central portion is maintained at a temperature of about 930 °C to about 970 °C.

[0163] Aspect 79 provides the method of any one of Aspects 77-78, wherein the method comprises maintaining the dried extruded composition at a preheat distance from the unheated insertion portion for a preheat duration before inserting the dried extruded composition into the furnace, wherein the preheat distance is 0.01 m to 0. 1 m and the preheat duration is 1 min to 10 min.

[0164] Aspect 80 provides the method of any one of Aspects 77-79, wherein a distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion is a total length of the furnace (L), wherein the method comprises moving the dried extruded composition through the furnace at a rate that is about 0.01*L per 1 min to 0. 1*L per 1 min, further comprising holding the dried extruded composition stationary in the heated central portion for a heating duration that is 5 min to 1 h.

[0165] Aspect 81 provides the method of Aspect 80, the rate is 0.03*L to 0.07*L.

[0166] Aspect 82 provides the method of any one of Aspects 80-81, wherein the heating duration is 10 min to 30 min.

[0167] Aspect 83 provides the method of any one of Aspects 77-82, wherein the firing is completed in a duration of 20 min to 2 h.

[0168] Aspect 84 provides the method of any one of Aspects 77-83, wherein the firing is completed in a duration of 30 min to 1 h.

[0169] Aspect 85 provides the method of any one of Aspects 77-84, wherein the extrudable composition comprises hollow glass beads.

[0170] Aspect 86 provides a method of forming a porous substrate, the method comprising: extruding an extrudable composition, the extrudable composition comprising a binder and / or sintering aid, and graphite particles comprising graphite plates, graphite flakes, or a combination thereof; drying the extruded composition; and firing the dried extruded composition, to form the porous substrate, wherein the porous substrate comprises a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure, wherein a total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry; wherein the porous substrate is conductive to electricity.

[0171] Aspect 86 provides a method of forming a porous substrate, the method comprising: extruding an extrudable composition, the extrudable composition comprising a binder and / or sintering aid, graphite particles comprising graphite plates, graphite flakes, or a combination thereof, and hollow glass beads; drying the extruded composition; and firing the dried extruded composition, to form the porous substrate, wherein the firing comprises firing the dried extruded composition in a furnace comprising an unheated insertion portion, a heated central portion maintained at a temperature of about 920 °C to 1000 °C, and an unheated exit portion, wherein a distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion is a total length of the furnace (L), wherein the method comprises moving the dried extruded composition through the furnace at a rate that is about 0.01*L per 1 min to 0.1 *L per 1 min, further comprising holding the dried extruded composition stationary in the heated central portion for a heating duration that is 5 min to 1 h, wherein the firing is completed in a duration of 20 min to 2 h;wherein the porous substrate comprises a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure, wherein a total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry; wherein the porous substrate is conductive to electricity.

[0172] Aspect 87 provides a method of forming a porous substrate, the method comprising: extruding an extrudable composition comprising a binder and / or sintering aid; drying the extruded composition; and firing the dried extruded composition, to form the porous substrate; wherein the firing comprises firing the dried extruded composition in a furnace comprising an unheated insertion portion, a heated central portion maintained at a temperature of about 920 °C to 1000 °C, and an unheated exit portion.

[0173] Aspect 88 provides the method of Aspect 87, wherein the heated central portion is maintained at a temperature of about 930 °C to about 970 °C.

[0174] Aspect 89 provides the method of any one of Aspects 87-88, wherein the method comprises maintaining the dried extruded composition at a preheat distance from the unheated insertion portion for a preheat duration before inserting the dried extruded composition into the furnace, wherein the preheat distance is 0.01 m to 0. 1 m and the preheat duration is 1 min to 10 min.

[0175] Aspect 90 provides the method of any one of Aspects 87-89, wherein a distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion is a total length of the furnace (L), wherein the method comprises moving the dried extruded composition through the furnace at a rate that is about 0.01*L per 1 min to 0. 1*L per 1 min, further comprising holding the dried extruded composition stationary in the heated central portion for a heating duration that is 5 min to 1 h.

[0176] Aspect 91 provides the method of Aspect 90, the rate is 0.03*L to 0.07*L.

[0177] Aspect 92 provides the method of any one of Aspects 90-91, wherein the heating duration is 10 min to 30 min.

[0178] Aspect 93 provides the method of any one of Aspects 87-92, wherein the firing is completed in a duration of 20 min to 2 h.

[0179] Aspect 94 provides the method of any one of Aspects 87-93, wherein the firing is completed in a duration of 30 min to 1 h.

[0180] Aspect 95 provides the method of any one of Aspects 87-94, wherein the extrudable composition comprises hollow glass beads.

[0181] Aspect 96 provides a method of forming a porous substrate, the method including: extruding an extrudable composition including a binder and / or sintering aid, and hollow glass beads; drying the extruded composition; and firing the dried extruded composition, to form the porous substrate; wherein the firing includes firing the dried extruded composition in a furnace including an unheated insertion portion, a heated central portion maintained at a temperature of about 920 °C to 1000 °C, and an unheated exit portion; wherein a distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion is a total length of the furnace (L), wherein the method includes moving the dried extruded composition through the furnace at a rate that is about 0.01*L per 1 min to 0. 1*L per 1 min, further including holding the dried extruded composition stationary in the heated central portion for a heating duration that is 5 min to 1 h, wherein the firing is completed in a duration of 20 min to 2 h.

[0182] Aspect 97 provides a method of using the porous substrate of any one of Aspects 37- 42, the method comprising: exposing the porous substrate to a gas stream including CO2 to at least partially adsorb the CO2 from the gas-stream into the coating on the porous substrate; and desorbing the CO2 from the coating on the porous substrate, the desorbing comprising applying an electrical potential across the porous substrate to heat the porous substrate.

[0183] Aspect 98 provides the porous substrate or method of any one or any combination of Aspects 1-97 optionally configured such that all elements or options recited are available to use or select from.

Claims

CLAIMSWhat is claimed is:1 . A porous substrate comprising: a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure, wherein a total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry; wherein the porous substrate is conductive to electricity due to the continuous graphitic phase.

2. The porous substrate of claim 1, wherein the continuous graphitic phase is homogeneously distributed in the glass and / or ceramic phase.

3. The porous substrate of any one of claims 1-2, wherein the porous substrate has an electrical resistance of 1 ohm to 1,000 ohms.

4. The porous substrate of any one of claims 1-3, wherein the porous substrate has a bulk density of 0.5 g / cm3to 1.5 g / cm3, the total pore volume of the porous substrate is 40% to 95% as determined by mercury porosimetry, and wherein the porous substrate has a closed frontal area of 10% to 40%.

5. The porous substrate of any one of claims 1-4, wherein the graphitic phase comprises graphite plates, graphite flakes, natural graphite, synthetic graphite, or a combination thereof; or an extruded and fired product of graphite plates, graphite flakes, natural graphite, synthetic graphite, or a combination thereof; or a combination thereof.

6. The porous substrate of any one of claims 1-5, wherein the graphitic phase comprises graphite particles that comprise an elongated morphology, wherein the porous substrate is an extruded product of an extrudable composition, wherein the majority of the graphite particleshave a longitudinal axis and / or an axis orthogonal to the height thereof oriented within 45° to a direction of extrusion.

7. The porous substrate of claim 6. wherein the porous substrate has a greater electrical conductivity along a cell wall as compared to an electrical conductivity through the cell wall.

8. The porous substrate of any one of claims 1-7, wherein the graphitic phase is 2 wt% to 30 wt% of the porous substrate, and wherein the glass and / or ceramic phase is 10 wt% to 70 wt% of the porous substrate.

9. The porous substrate of any one of claims 1-8, wherein flexural strength in a 4-point bend test of the porous substrate normalized by CFA of the porous substrate is 500 psi to 2,500 psi.

10. The porous substrate of any one of claims 1-9, wherein the porous 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, wherein the porous substrate has a cell density of 20 cells per square inch to 1,000 cells per square inch and a wall thickness of 0.002 inches to 0.05 inches.

11. The porous substrate of any one of claims 1-10, wherein the porous substrate comprises a coating thereon, the coating comprising a sorbent that adsorbs and desorbs CO2, a catalyst, or a combination thereof.

12. The porous substrate of any one of claims 1-11, wherein the porous substrate is electrically conductive in both an axial direction of the substrate and in a lateral direction transverse to the axial direction.

13. A porous substrate comprising: a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure, wherein a total pore volume of the porous substrate is 40% to 95% as determined by mercury porosimetry; anda coating on the continuous interconnected pore structure, the coating comprising a catalyst, a sorbent that adsorbs and desorbs CO2, or a combination thereof; wherein the porous substrate is conductive to electricity.

14. A method of using the porous substrate of any one of claims 12-13, the method comprising: exposing the porous substrate to a gas stream including CO2 to at least partially adsorb the CO2 from the gas-stream into the coating comprising the sorbent on the porous substrate; and desorbing the CO2 from the coating on the porous substrate, the desorbing comprising applying an electrical potential across the porous substrate to heat the porous substrate.

15. The porous substrate of any one of claims 1-14, wherein the porous substrate is an extruded and fired product of an extrudable composition, the extrudable composition comprising: a binder and / or sintering aid; and graphite particles.

16. The porous substrate of claim 15, wherein the binder and / or sintering aid is 10 wt% to 70 wt% of the extrudable composition, and wherein the graphite particles are 2 wt%to 30 wt% of the extrudable composition, based on a dry weight of the extrudable composition.

17. The porous substrate of any one of claims 15-16, wherein the binder and / or sintering aid comprises an inorganic binder, a polymer, a thermosetting resin, a carbon precursor, a borate, a phosphate, a transition metal oxide, an oxide, a hydroxide, a carbonate, a silicate, an alumino-silicate, or a combination thereof.

18. The porous substrate of any one of claims 15-17, wherein the graphite particles are graphite plates, graphite flakes, or a combination thereof, wherein the graphite particles have a median longest dimension of 1 micron to 100 microns, and wherein the graphite particles have an aspect ratio of 1 :5 to 1: 15.

19. A porous substrate comprising: an extruded and fired product of an extruded extrudable composition, the extrudable composition comprising a binder and / or sintering aid, and graphite particles comprising graphite plates, graphite flakes, or a combination thereof; wherein the porous substrate comprises a continuous graphitic phase, and a glass and / or ceramic phase, wherein the graphitic phase and the glass and / or ceramic phase together form a continuous interconnected pore structure, wherein a total pore volume of the porous substrate is at least 40% as determined by mercury porosimetry; wherein the porous substrate is conductive to electricity.

20. A method of forming the porous substrate of any one of claims 15-19, the method comprising: extruding the extrudable composition; drying the extruded composition; and firing the dried extruded composition, to form the porous substrate.

21. A method of forming a porous substrate, the method including: extruding an extrudable composition including a binder and / or sintering aid, and hollow glass beads; and firing the extruded composition, to form the porous substrate; wherein the firing includes firing the extruded composition in a furnace including an unheated insertion portion, a heated central portion maintained at a temperature of about 920 °C to 1000 °C, and an unheated exit portion; wherein a distance from an entrance of the unheated insertion portion to an exit of the unheated exit portion is a total length of the furnace (L), wherein the method includes moving the extruded composition through the furnace at a rate that is about 0.01*L per 1 min to 0. 1*L per 1 min, further including holding the extruded composition stationary in the heated central portion for a heating duration that is 5 min to 1 h, wherein the firing is completed in a duration of 20 min to 2 h.

Images