Mixed metal oxide catalysts and compositions and processes for their production - Patents.com

Abstract

Mixed metal oxide compositions and mixed metal oxide catalysts are provided. The mixed metal oxide compositions and mixed metal oxide catalysts include aluminum, cobalt, and copper, and at least a portion of the compositions include a ternary spinel structure. Processes for preparing the mixed metal oxide catalysts and methods for reducing pollutants using the mixed metal oxide compositions or mixed metal oxide catalysts described herein are also provided.

Description

[Technical Field]

[0001] The present invention relates to mixed metal oxide catalysts and compositions. More particularly, the present invention relates to mixed metal oxide catalysts and compositions containing aluminum, cobalt, and copper, their uses, and processes for their preparation. [Background technology]

[0002] Catalysts that increase the rate of chemical reactions can be provided in the form of catalytic converters. Three-way catalytic converters, the primary emission control technology used in internal combustion engines, oxidize carbon monoxide (CO) and hydrocarbons (HC) to produce carbon dioxide (CO2) and water, and nitrogen oxides (NO X ) can be reduced to produce nitrogen. CO, HC, and NO X Reducing the amount of catalytic converters used in internal combustion engines has a positive impact on the environment by lowering the levels of these harmful chemicals produced by internal combustion engines. In light of stricter emissions regulations and guidelines being implemented in various countries and jurisdictions, there is a need for better performing catalytic converters for internal combustion engines.

[0003] Proper functioning of a three-way catalytic converter requires a balance between oxidation and reduction reactions to ensure optimal conversion of pollutants. The ability to undergo oxidation and reduction reactions can be affected by the presence of air, as air contains gases such as oxygen. In an ideal internal combustion engine system, a precise amount of air is supplied to completely combust all fuels within the engine, referred to as operating at a stoichiometric mixture or stoichiometric conditions. In practice, this is not currently achievable, and therefore three-way catalytic converters may operate under substantially non-ideal conditions or non-stoichiometric conditions using oxygen monitoring and control systems. The control system, in combination with an oxygen monitor, allows the fuel to oscillate between lean and rich fuel conditions, where excess air in the combustion chamber can characterize lean conditions during combustion and excess fuel in the combustion chamber can characterize rich conditions during combustion. Under stoichiometric conditions, the engine is operating at a lambda value of 1, with values ​​greater than 1 representing lean conditions and values ​​less than 1 representing rich conditions.

[0004] Rich-burn combustion requires only a single three-way catalyst, thereby reducing engine temperature and increasing engine power; however, rich-burn combustion can increase overall fuel consumption, which in turn can increase the amount of pollutants produced during combustion. Furthermore, under rich-burn conditions, NO X Oxidation reactions, such as those that reduce CO₂, can be significantly impaired, thus requiring additional features. Lean conditions can increase fuel efficiency; however, these conditions increase engine temperatures.

[0005] Conventional catalysts may use metals, such as platinum group metals, including, for example, platinum, rhodium, and palladium, to catalyze oxidation and reduction reactions. These catalysts may be formed as compositions or catalyst precursors for application to support materials, substrates, or other materials that may facilitate the formation of a catalyst or catalytic converter. The combination of metals, as well as their amounts and ratios in the catalyst, significantly alters their ability to function as a catalyst or catalytic converter due to their inherent thermal stability and ability to undergo oxidation and reduction reactions at the required and / or desired reaction initialization temperature, operating temperature, or oxygen content.

[0006] For example, conventional three-way catalytic converters, such as those described in U.S. Pat. No. 1,207,662 B2, use expensive and rare metals, such as platinum group metals, to reduce emissions. In addition to the high cost of producing such catalysts containing rare or expensive metals, the conversion of emissions to less harmful species can be limited.

[0007] WO2019204127A1 teaches mixed metal oxide compositions containing ratios of the elements aluminum to cobalt to copper that reduce the reaction initialization temperature. WO2019204127A1 further teaches that low Al content reduces the utility of the disclosed catalyst, while increasing the Al content does not affect utility, and therefore an elemental ratio of Al:Co:Cu of 3:2:1 is preferred.

[0008] Existing mixed metal oxide compositions and catalysts produce NO at lambda values ​​close to stoichiometry. X Therefore, the ability to reduce NO is limited. X There remains a need for catalytic converters and catalysts that more efficiently reduce CO₂. Summary of the Invention

[0009] The present disclosure provides mixed metal oxide catalyst precursors or compositions and mixed metal oxide catalysts containing aluminum, cobalt, and copper, and processes for their preparation. The mixed metal oxide catalysts can provide one or more of the following improved characteristics when compared to conventional compositions and catalysts, including increased stability, extended life, increased emission reductions, NOx reduction, and the like. X These include, but are not limited to, increased reduction, increased CO reduction, increased hydrocarbon reduction, improved operating temperature, increased oxidation potential, increased reduction potential, lower reaction initialization temperature, improved lean fuel emission reduction, improved rich fuel emission reduction, ease of manufacturing, reduced amount of catalyst composition used, improved usability over a range of lambda values, and lower manufacturing costs.

[0010] In one aspect of the disclosure, provided herein is a mixed metal oxide catalyst comprising aluminum, cobalt, and copper, wherein the elemental ratio of aluminum to cobalt to copper can be X:Y:1, where X is in the range of about 1 to about 80 and Y is in the range of about 1 to about 39, and at least a portion of the catalyst comprises a ternary spinel structure. The catalyst can also comprise aluminum in an amount equal to or greater than the amount of cobalt.

[0011] In various embodiments, X can be in the range of about 5 to about 20, and Y can be in the range of about 2 to about 19. In various embodiments, X can be in the range of about 5 to about 20, and Y can be in the range of about 2 to about 19, and the catalyst comprises aluminum in an amount equal to or greater than the amount of cobalt.

[0012] In various embodiments, X can be in the range of about 7 to about 20, and Y can be in the range of about 3 to about 15. In various embodiments, X can be in the range of about 7 to about 20, and Y can be in the range of about 3 to about 15, and the catalyst comprises aluminum in an amount equal to or greater than the amount of cobalt.

[0013] In various embodiments, X can be in the range of about 7 to about 18, and Y can be in the range of about 3 to about 13. In various embodiments, X can be in the range of about 7 to about 18, and Y can be in the range of about 3 to about 13, and the catalyst comprises aluminum in an amount equal to or greater than the amount of cobalt.

[0014] In various embodiments, X can be in the range of about 7 to about 12, and Y can be in the range of about 3 to about 15. In various embodiments, X can be in the range of about 7 to about 12, and Y can be in the range of about 3 to about 15, and the catalyst comprises aluminum in an amount equal to or greater than the amount of cobalt.

[0015] In various embodiments, X can be in the range of about 8 to about 20, and Y can be in the range of about 3 to about 15. In various embodiments, X can be in the range of about 8 to about 20, and Y can be in the range of about 3 to about 15, and the catalyst comprises aluminum in an amount equal to or greater than the amount of cobalt.

[0016] In various embodiments, X can be in the range of about 7 to about 20, and Y can be in the range of about 2 to about 19. In various embodiments, X can be in the range of about 7 to about 20, and Y can be in the range of about 2 to about 19, and the catalyst comprises aluminum in an amount equal to or greater than the amount of cobalt.

[0017] In various embodiments, the elemental ratio of aluminum to cobalt to copper is about 80:39:1, about 24:5:1, about 1.5:2:1, about 2.2:2:1, about 4:1:1, about 2.33:3.33:1, about 3:1.6:1, about 3:2.5:1, about 12:2:1, about 8:1:1, about 4:2:1, about 6:23:1, about 40:19:1, about 3:2:1, about 5:9: The ratio may be about 6.67:2.33:1, about 6:8:1, about 6:2:1, about 5:4:1, about 10:19:1, about 6:2.7:1, about 10:4:1, about 20:9:1, about 14:15:1, about 9:5:1, about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1 or about 8:6:1.

[0018] In various embodiments, the elemental ratio of aluminum to cobalt to copper can be about 6.67:2.33:1, about 6:8:1, about 6:2:1, about 5:4:1, about 10:19:1, about 6:2.7:1, about 10:4:1, about 20:9:1, about 14:15:1, about 9:5:1, about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1, or about 8:6:1.

[0019] In various embodiments, the elemental ratio of aluminum to cobalt to copper can be about 10:4:1, about 20:9:1, about 14:15:1, about 9:5:1, about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1, or about 8:6:1.

[0020] In various embodiments, the elemental ratio of aluminum to cobalt to copper can be about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1, or about 8:6:1.

[0021] In various embodiments, the mixed metal oxide catalyst may further comprise a support material.

[0022] In various embodiments, Cu +2 and Co +2 Ions may share the A site of the spinel structure; Co +3 and Al +3 The ions may share the B site of the spinel structure.

[0023] In various embodiments, the x-ray diffraction pattern of the mixed metal oxide catalyst may not have peaks associated with gamma alumina.

[0024] In various embodiments, the mixed metal oxide catalyst may further include a noble metal or a rare earth element.

[0025] In various embodiments, the mixed metal oxide catalyst may further include a dopant.

[0026] In various embodiments, the dopant may be substituted for cobalt in approximately equimolar amounts.

[0027] In various embodiments, the dopant may be substituted at about 0.1% to about 20%.

[0028] In various embodiments, the dopant may include cerium and / or manganese.

[0029] In various embodiments, provided herein are catalysts prepared using the mixed metal oxide compositions or catalyst precursors described herein.

[0030] In various embodiments, the support material may be uniformly dispersed in the composition or catalyst precursor, or the composition or catalyst precursor may be uniformly dispersed on the support material.

[0031] In various embodiments, the composition or catalyst precursor may be deposited on a base layer of a support material.

[0032] In various embodiments, the support material may be added to the composition or catalyst precursor prior to dispersion.

[0033] In various embodiments, the composition or catalyst precursor may be applied to a substrate.

[0034] In various embodiments, the substrate may be porous.

[0035] In various embodiments, the substrate may include cordierite, alumina, zirconia, magnesium oxide, metal honeycomb, or ceramic beads.

[0036] In various embodiments, applying to the substrate can include coating the substrate such that the composition or catalyst precursor can be uniformly distributed on the substrate.

[0037] In various embodiments, the coating can include filling the pores of the substrate.

[0038] In various embodiments, the total support composition can be from about 10% to about 150% by weight of the total catalyst weight.

[0039] In various embodiments, the total support composition can be from about 40% to about 60% by weight of the total catalyst weight.

[0040] In various embodiments, applying to the substrate can include dipping the substrate into the composition or dispersion of the catalyst precursor.

[0041] In various embodiments, the reaction initialization temperature for using a mixed metal oxide catalyst can be less than about 350°C.

[0042] In various embodiments, the catalyst may be for use in a catalytic converter.

[0043] In another aspect of the present disclosure, there is provided herein a method for removing one or more contaminants from a gas stream, comprising exposing the gas stream to a catalyst described herein.

[0044] In various embodiments, the gas stream may include a gas stream, an exhaust gas stream, a flue gas, a flue exhaust, a diesel exhaust, a kerosene exhaust, or any combination thereof.

[0045] In various embodiments, the pollutants may include carbon monoxide, nitrogen oxides, hydrocarbons, or any combination thereof.

[0046] In various embodiments, exposing the gas stream to the catalyst can be at an operating temperature of about 300°C to about 700°C.

[0047] In various embodiments, the reaction initiation temperature for catalysis using a catalyst can be less than about 350°C.

[0048] In another aspect of the present disclosure, there is provided a process for preparing a catalyst, comprising: (a) preparing a dispersion comprising a metal solution, wherein the metal solution comprises a solvent and aluminum, copper, and cobalt in solution, and wherein the total concentration of the metal ions in the solution can be from about 0.5 M to about 5 M; (b) applying the dispersion to a substrate; (c) removing the solvent from the substrate to form a catalyst precursor or composition; and (d) calcining the catalyst precursor or composition to produce a catalyst, wherein the catalyst comprises an elemental ratio of aluminum to cobalt to copper of X:Y:1, wherein X can be in the range of from about 1 to about 80 and Y can be in the range of from about 1 to about 39. Provided herein is a process comprising:

[0049] In various embodiments, X is in the range of about 5 to about 20, and Y is in the range of about 2 to about 19. In various embodiments, X is in the range of about 5 to about 20, and Y is in the range of about 2 to about 19, and the amount of aluminum is equal to or greater than the amount of cobalt.

[0050] In various embodiments, X is in the range of about 7 to about 20, and Y is in the range of about 3 to about 15. In various embodiments, X is in the range of about 7 to about 20, Y is in the range of about 3 to about 15, and the amount of aluminum is equal to or greater than the amount of cobalt.

[0051] In various embodiments, X is in the range of about 7 to about 18, and Y is in the range of about 3 to about 13. In various embodiments, X is in the range of about 7 to about 18, Y is in the range of about 3 to about 13, and the amount of aluminum is equal to or greater than the amount of cobalt.

[0052] In various embodiments, X is in the range of about 8 to about 20, and Y is in the range of about 3 to about 15. In various embodiments, X is in the range of about 8 to about 20, Y is in the range of about 3 to about 15, and the amount of aluminum is equal to or greater than the amount of cobalt.

[0053] In various embodiments, X is in the range of about 7 to about 20, and Y is in the range of about 3 to about 15. In various embodiments, X is in the range of about 7 to about 20, Y is in the range of about 3 to about 15, and the amount of aluminum is equal to or greater than the amount of cobalt.

[0054] In various embodiments, X is in the range of about 7 to about 20, and Y is in the range of about 2 to about 19. In various embodiments, X is in the range of about 7 to about 20, Y is in the range of about 2 to about 19, and the amount of aluminum is equal to or greater than the amount of cobalt.

[0055] In various embodiments, the elemental ratio of aluminum to cobalt to copper is about 80:39:1, about 24:5:1, about 1.5:2:1, about 2.2:2:1, about 4:1:1, about 2.33:3.33:1, about 3:1.6:1, about 3:2.5:1, about 12:2:1, about 8:1:1, about 4:2:1, about 6:23:1, about 40:19:1, about 3:2:1, about 5:9: The ratio may be about 6.67:2.33:1, about 6:8:1, about 6:2:1, about 5:4:1, about 10:19:1, about 6:2.7:1, about 10:4:1, about 20:9:1, about 14:15:1, about 9:5:1, about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1 or about 8:6:1.

[0056] In various embodiments, the elemental ratio of aluminum to cobalt to copper can be about 6.67:2.33:1, about 6:8:1, about 6:2:1, about 5:4:1, about 10:19:1, about 6:2.7:1, about 10:4:1, about 20:9:1, about 14:15:1, about 9:5:1, about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1, or about 8:6:1.

[0057] In various embodiments, the elemental ratio of aluminum to cobalt to copper can be about 10:4:1, about 20:9:1, about 14:15:1, about 9:5:1, about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1, or about 8:6:1.

[0058] In various embodiments, the elemental ratio of aluminum to cobalt to copper can be about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1, or about 8:6:1.

[0059] In various embodiments, the aluminum, copper, and cobalt in the metal solution may each independently be an oxide, a salt, an organometallic complex, or any combination thereof.

[0060] In various embodiments, the aluminum, copper, and cobalt salts may be aluminum nitrate, copper nitrate, and cobalt nitrate.

[0061] In various embodiments, the catalyst precursor may further include a support material.

[0062] In various embodiments, the support material can be added to the dispersion during step (a).

[0063] In various embodiments, applying the dispersion to the substrate can include distributing the dispersion evenly on the substrate.

[0064] In various embodiments, the substrate may be porous.

[0065] In various embodiments, the applying step can include filling pores in the substrate.

[0066] In various embodiments, the applying step can include dipping the substrate into the dispersion.

[0067] In one embodiment, the substrate may include cordierite, alumina, zirconia, magnesium oxide, metal honeycomb, or ceramic beads.

[0068] In various embodiments, the total support dispersion can be from about 10% to about 150% by weight of the catalyst.

[0069] In various embodiments, the total support dispersion can be from about 40% to about 60% by weight of the catalyst.

[0070] In various embodiments, the solvent may include water or acetone.

[0071] In various embodiments, removing the solvent from the substrate to form a catalyst precursor can include evaporating the solvent.

[0072] In various embodiments, the step of removing the solvent from the substrate to form a catalyst precursor can further include rolling the substrate.

[0073] In various embodiments, the step of calcining the catalyst precursor can include a temperature of from about 800° C. to about 1000° C. for from about 10 minutes to about 60 minutes.

[0074] In various embodiments, the calcination step may be carried out in air.

[0075] In various embodiments, steps (b) through (d) may be repeated one or more times to produce the catalyst.

[0076] In various embodiments, the catalyst may be used as a catalytic converter.

[0077] Other aspects and features of the present invention will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the invention in conjunction with the appended claims. [Brief explanation of the drawings]

[0078] In the drawings illustrating an embodiment of the present disclosure:

[0079] [Figure 1] FIG. 1 provides NOX conversion over a range of lambda values ​​for mixed metal oxide catalysts according to various embodiments of the present disclosure.

[0080] [Figure 2]FIG. 2 provides NOx conversion over a range of lambda values ​​for mixed metal oxide catalysts according to embodiments of the present disclosure.

[0081] [Figure 3] FIG. 3 provides an illustration of the relative performance of various mixed metal oxide catalysts containing various ratios of Al:Co:Cu.

[0082] [Figure 4] FIG. 4 shows a flow diagram of one embodiment of the process described herein that may be carried out to obtain the mixed metal oxide catalysts described herein.

[0083] [Figure 5] FIG. 5 provides the NOx conversion at 0.995 lambda for mixed metal oxide catalysts containing dopants according to embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0084] In the context of this disclosure, various terms are used in accordance with what is understood to be the ordinary meaning of those terms.

[0085] Described herein are mixed metal oxide compositions or catalyst precursors and mixed metal oxide catalysts, and processes for their preparation. It will be understood that the embodiments and examples are provided herein for illustrative purposes directed to those skilled in the art and are not intended to be limiting in any way.

[0086] As used herein, the term "about" refers to about a + / - 10% variation from a given value. It should be understood that such a variation is always included in any given value provided herein, whether or not it is specifically referred to.

[0087] As used herein, the term "substantially" refers to about a + / - 5% variation from a given value. When no value is used, substantially means nearly complete, but perhaps with some variation, contamination, and / or additional components. In some embodiments, "substantially" can include completely.

[0088] As used herein, the term "catalyst" may refer to any material that increases the rate at which a reaction occurs. A catalyst is not consumed in a reaction, but may be altered by the reaction. A catalyst generally reacts with one or more reactants to form an intermediate, which then gives the final reaction product. A catalyst may be a catalyst that reacts with NO X The catalyst may be suitable for use in engines, such as internal combustion engines, to catalyze the reaction of harmful emissions, such as CO, and hydrocarbons, to produce less harmful emissions, such as nitrogen, oxygen, and carbon dioxide. It is contemplated that catalysts may be present in other engines, machines, technologies, etc., to reduce harmful emissions.

[0089] As used herein, the term "properties" with respect to the functionality of mixed metal oxide catalysts includes increased stability, extended life, increased emission reductions, NO X These properties may include, but are not limited to, one or more of: increased CO reduction, increased hydrocarbon reduction, improved operating temperature, increased oxidation potential, increased reduction potential, lower reaction initialization temperature, increased lean fuel emission reduction, increased rich fuel emission reduction, increased emissions reduction over a range of lambda values, increased emission reduction over a range of lambda values ​​near 1, ease of manufacture, reduced amount of catalyst composition required for use, increased usability over a range of lambda values, and reduced manufacturing costs. It is contemplated that a list of "properties" related to the functionality of a mixed metal oxide catalyst may encompass any one or more of these properties, whether or not each is individually listed.

[0090] As used herein, the term "gas" may include a phase of matter and / or a combustible fuel used to generate energy, such as, for example, gasoline, diesel, kerosene, propane, or other combustible fuel.

[0091] Compositions and catalysts In various embodiments disclosed herein, a mixed metal oxide catalyst is provided comprising aluminum, cobalt, and copper, wherein the elemental ratio of aluminum to cobalt to copper is X:Y:1, where X is in the range of about 1 to about 80 and Y is in the range of about 1 to about 39, and at least a portion of the catalyst comprises a ternary spinel structure.

[0092] A mixed metal oxide catalyst refers to a catalyst containing two or more metal oxides. The metal oxide may include metal and oxygen, more specifically, metal cations and oxide anions. The metal oxide may be formed by a chemical reaction involving metal cations and oxygen. The metal cation may be any metal, particularly copper, aluminum, and cobalt, in any cationic form suitable for the application defined herein.

[0093] As referred to herein, "elemental ratio" may be defined as the abundance of a metal element in a composition or catalyst compared to other metal element(s) in the composition or catalyst. The abundance or amount of a metal element may be determined using moles, mole ratios, percentages, or any equivalent value in light of the teachings herein. In certain embodiments, the abundance or amount of a metal element(s) may be expressed as its abundance or amount per unit area, surface area, volume, or any equivalent value in light of the teachings herein. As used herein, the elemental form of a metal refers to the amount of a metal present in a composition or catalyst that may be covalently or non-covalently bound to other chemicals or molecules, such as Al. 3+ , Cu 2+ , or Co 2+ Thus, the ratio may refer to the amount of metal relative to other metals in a mixed metal oxide composition or catalyst, without regard to additional groups such as oxide, nitrate, or other additional elements or molecules.

[0094] In certain embodiments, the mixed metal oxide composition or catalyst may comprise aluminum, cobalt, and copper, wherein the elemental ratio of aluminum to cobalt to copper is X:Y:1, where X is in the range of about 1 to about 80 and Y is in the range of about 1 to about 39. In certain embodiments, the metallic element copper may be assigned a value of 1 in the mixed metal oxide composition or catalyst ratio. As known to those skilled in the art, a value of 1 for copper in a ratio provides a means of normalizing the amount of other metallic elements present in the composition or catalyst. The value of 1 in a ratio may not substantially correspond to the absolute amount of the element, but refers to its amount relative to the other metallic element(s) included in the composition or catalyst. In certain embodiments, copper may be independently present in an amount equal to or less than cobalt or aluminum. In certain further embodiments, the composition or catalyst may include an amount of aluminum equal to or greater than the amount of cobalt. In certain embodiments, each of the metal elements X and Y may independently represent any value recited in the ratios therein, and it is contemplated that X may independently include any value from about 1 to about 80, and Y may independently include any value from about 1 to about 39. In certain embodiments, the values ​​of X are independently 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121 X may be 1, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80, and the value of Y may independently be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, or 39. In certain embodiments, X may be in the range of 7 to 12, and Y may be in the range of 3 to 15. In certain embodiments, X may be in the range of 7 to 18, and Y may be in the range of 3 to 13. In certain embodiments, X can range from 5-20 and Y can range from 2-19.In certain embodiments, X can be in the range of 8 to 20, and Y can be in the range of 3 to 15. In certain embodiments, X can be in the range of 7 to 20, and Y can be in the range of 3 to 15. In certain embodiments, X can be in the range of 7 to 20, and Y can be in the range of 2 to 19. In certain embodiments, the elemental ratio of aluminum to cobalt to copper is about 80:39:1, about 24:5:1, about 1.5:2:1, about 2.2:2:1, about 4:1:1, about 2.33:3.33:1, about 3:1.6:1, about 3:2.5:1, about 12:2:1, about 8:1:1, about 4:2:1, about 6:23:1, about 40:19:1, about 3:2:1, about 5:9: The ratio of aluminum to cobalt to copper may be X:Y:1, about 6.67:2.33:1, about 6:8:1, about 6:2:1, about 5:4:1, about 10:19:1, about 6:2.7:1, about 10:4:1, about 20:9:1, about 14:15:1, about 9:5:1, about 16:13:1, about 7:7:1, about 12:3.4:1, about 9.5:4.5:1, about 18:11:1, about 12:7:1, or about 8:6:1. In certain embodiments, the mixed metal oxide composition or catalyst may comprise aluminum, cobalt, and copper, and the elemental ratio of aluminum to cobalt to copper may be X:Y:1, where X is not in the range of about 1 to about 3 and Y is not in the range of about 1.4 to about 6.

[0095] In certain embodiments, the mixed metal oxide composition or catalyst may comprise metal oxides of aluminum, cobalt, and copper. The mixed metal oxide catalyst may be in a substantially solid form, and the solid form may comprise a crystalline solid or any equivalent solid known to those skilled in the art in light of the teachings herein. A crystalline solid comprises a solid structure in which the molecules forming the crystalline solid may have a well-defined arrangement. In certain embodiments, the crystalline solid may comprise, at least in part, a ternary spinel structure. A spinel structure is a crystal structure having the general formula AB2X4, where A and B are cations and X is an anion. A spinel structure has a face-centered cubic close-packed arrangement of 32 anions, with voids occupied by metal ions. As used herein, a spinel structure may refer to a spinel structure, a spinel-like structure, or any equivalent known to those skilled in the art. In certain embodiments, the octahedral site of a spinel may be referred to as a B-site, and the tetrahedral site of a spinel may be referred to as an A-site. In certain embodiments, Cu 2+ and Co 2+ The ions may share the A site of the spinel structure, and Co 3+ and Al 3+ The ions may share the B site of a spinel structure, which may be represented by the formula (CuCo)(CoAl)O. In certain embodiments, the catalyst may include additional crystalline or amorphous moieties.

[0096] As known to those skilled in the art, spinel structure can be determined using a variety of techniques, including, but not limited to, X-ray diffraction, tunneling microscopy, or photoelectron spectroscopy. In certain embodiments, the catalyst may be free of X-ray diffraction peaks associated with gamma alumina. In certain embodiments, the spinel structure of the catalyst may be characterized by an X-ray diffraction pattern lacking a peak at {222}. In certain embodiments, the spinel structure of the catalyst may be characterized by an X-ray diffraction pattern having a low intensity ratio between the {222} and {311} peaks. In certain embodiments, the ratio of the {222} and {311} peaks of the catalyst may be less than about 0.1.

[0097] In certain embodiments, the composition or catalyst may further comprise a support material. The support material used herein may be used to disperse the composition or catalyst. The support material may distribute the composition or catalyst over a large surface area. The support material may be selected to provide a smooth surface or a rough or irregular surface, which may increase the surface area compared to a surface without the support material. The support material may also affect the performance of the catalyst, such as its performance at a specific temperature and long-term stability. The support material may also provide oxygen storage and release, which may improve the performance of the catalyst during lean and rich fuel operation of the engine. Selecting a more stable and durable catalyst may be advantageous, as these properties may allow for easier installation or closer placement of the catalyst to the engine and / or extend the catalyst's lifespan. In certain embodiments herein, the support material may comprise alumina, silica, titania, zirconia, yttrium-stabilized zirconia, zirconium oxide, any support known to those skilled in the art, or any combination thereof, in light of the teachings herein.

[0098] In certain embodiments, the composition or catalyst may further comprise a noble metal or rare earth element. As used herein, "noble metal" may refer to any naturally occurring metallic chemical element that has a high current economic value compared to other metallic chemical elements, such as, for example, rhodium, platinum, gold, palladium, iridium, osmium, rhenium, ruthenium, germanium, beryllium, silver, indium, gallium, tellurium, bismuth, or mercury. As used herein, "rare earth element" may refer to elements including scandium, yttrium, lanthanum, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

[0099] In certain embodiments, the composition or catalyst may further comprise a dopant. As used herein, the term "dopant" or "dopant" may refer to an element introduced into a composition or material, such as a catalyst, that changes the properties of the composition or material. In certain embodiments, a dopant may change one or more of the following properties of the composition or catalyst to which it is added, including increased stability, increased lifetime, increased emission reduction, NOx reduction, and the like. XThese include, but are not limited to, increased CO reduction, increased hydrocarbon reduction, improved operating temperature, increased oxidation potential, increased reduction potential, lower reaction initialization temperature, increased lean fuel emission reduction, increased rich fuel emission reduction, ease of manufacturing, reduced catalyst composition amount used, and / or reduced manufacturing costs. In certain embodiments, a dopant may include any trace material that alters at least the properties of the composition or catalyst. In certain embodiments, a dopant may include cerium, manganese, or any combination thereof. In certain embodiments, the amount of dopant added to a composition or catalyst to alter the properties of the composition or catalyst may be very small. In certain embodiments, a dopant may be substituted for an equimolar amount of metal in the composition or catalyst. For example, the dopant may be substituted by about 0.1% to about 20%, or any value therebetween. In certain embodiments, the dopant is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3.0%, 3.1%, 3.1%. %,2.9%,3%,3.1%,3.2%,3.3%,3.4%,3.5%,3.6%,3.7%,3.8%,3.9%,4%,4.1%,4.2%,4.3%,4.4%,4.5%,4.6%,4.7%,4.8%,4.9%,5%,5.1%,5.2%,5.3%,5.4%,5.5%,5.6%,5.7%,5.8%,5.9%,6 %,6.1%,6.2%,6.3%,6.4%,6.5%,6.6%,6.7%,6.8%,6.9%,7%,7.1%,7.2%,7.3%,7.4%,7.5%,7.6%,7.7%,7.8%,7.9%,8%,8.1%,8.2%,8.3%,8.4%,8.5%,8.6%,8.7%,8.8%,8.9%,9%,9.1%,9 .2%, 9.3%, 9.4%, 9.5%, 9.6%, 9.7%, 9.8%, 9.9%, 10%, 10.1%, 10.2%, 10.3%, 10.4%, 10.5%, 10.6%, 10.7%, 10.8%, 10.9%, 11%, 11.1%, 11.2%, 11.3%, 11.4%, 11.5%, 11.6%, 11.7%, 11.8%, 11.9%, 12%, 12.1%, 12.2%, 12.3%, 12.4%, 12.5%, 12.6%, 12.7%, 12.8%, 12.9%, 13%, 13.1%, 13.2%, 13.3%, 13.4%, 13.5%, 13.6%, 13.7%, 13.8%, 13.9%, 14%, 14.1%, 14.2%, 14.3%, 14.4%, 14.5%, 14.6%, 14.7%, 14.8%, 14.9%, 15%, 15.1%, 15.2%, 15.3%, 15.4%, 15.5%, 15.6%, 15.7%, 15.8%, 15.9%, 16%, 16.1%, 16 0.2%, 16.3%, 16.4%, 16.5%, 16.6%, 16.7%, 16.8%, 16.9%, 17%, 17.1%, 17.2%, 17.3%, 17.4%, 17.5%, 17.6%, 17.7%, 17.8%, 17.9%, 18%, 18.1%, 18.2%, 18.3%, 18.4%, 18.5%, 18.6%, 18.7%, 18.8%, 18.9%, 19%, 19.1%, 19.2%, 19.3%, 19.4%, 19.5%, 19.6%, 19.7%, 19.8%, 19.9%, 20%, or any value therebetween. In various embodiments, the dopant may be substituted at about 0.1% to about 2%, or any value therebetween.

[0100] In certain further embodiments, the dopant may be replaced with an equimolar amount of cobalt, such that, for example, removing 1% of cobalt requires the addition of 1% of the dopant. In certain embodiments, it is contemplated that one or more dopants are added to the mixed metal oxide composition or catalyst. In certain embodiments, the dopant may improve one or more properties of the mixed metal oxide composition or catalyst.

[0101] In certain embodiments, the mixed metal oxide compositions or catalyst precursors described herein may be used to prepare catalysts. The catalysts may be used to convert CO, NO, and other CO2 from internal combustion engines into CO2. X and reactions that reduce harmful emissions such as hydrocarbon emissions. XThe catalyst may catalyze a reduction reaction, such as the reaction of CO or hydrocarbons to form water and CO. The catalyst may catalyze an oxidation reaction, such as the reaction of NO X The present invention may be used in combination with an engine, such as an internal combustion engine, to reduce the amount of one or more emissions, such as CO, and hydrocarbons.

[0102] In certain embodiments, the support material may be uniformly dispersed in the composition or dispersion, or the composition or dispersion may be uniformly dispersed on the support material. As used herein, the term "uniform" may refer to one feature, such as the composition, being substantially equally distributed on another feature, such as the support material. In certain embodiments, the composition or dispersion may be deposited, applied, or coated on a base layer of the support material. As used herein, "base layer" may refer to a surface, such as a support material, that may be substantially solid and capable of receiving the mixed metal oxide composition or dispersion. In certain other embodiments, the support material may be added to the composition or dispersion prior to dispersion so that the support material and the composition or dispersion are uniformly distributed within each other, resulting in a simultaneous uniform distribution of the composition or catalyst and the support material. Non-uniform distribution of the support material and / or the composition or dispersion may result in inconsistent performance across the catalyst or composition, with some areas performing poorly compared to other areas on the same support material, catalyst, or composition.

[0103] In certain embodiments, the composition or dispersion may be applied to a substrate. The substrate may include any substrate suitable for a catalyst based on its application or intended use, as known to those skilled in the art. In certain embodiments, the substrate may include a support material. In certain embodiments, the substrate may include cordierite, alumina, zirconia, magnesium oxide, a metal honeycomb, or ceramic beads. In certain embodiments, the composition or dispersion may be applied to a substrate so that the composition or dispersion can be uniformly distributed on the substrate. In certain embodiments, the substrate may be porous. The use of a porous substrate can increase the surface area of ​​the catalyst, which may improve one or more properties of the catalyst, including, but not limited to, increased emission reductions, extended lifespan, reduced preparation costs, and / or increased stability. In certain embodiments, the composition or dispersion may be applied to a substrate so that the composition can be uniformly distributed on the substrate. In certain embodiments, the substrate may be coated with the composition or dispersion. As used herein, the term "coating" may include applying a material, such as a composition, to a surface, such as a substrate, so that the material can be uniformly distributed. Uneven application or coating of the composition on the substrate can result in inconsistent properties across the coated substrate. In certain embodiments, coating the substrate with the composition or dispersion can include filling the pores of the substrate, and filling can include applying the composition or dispersion substantially completely and uniformly within the pores of the substrate. In certain embodiments, the substrate can be immersed in the dispersion of the composition. By immersing or surrounding the substrate during the dispersion of the composition, the composition can be applied uniformly on the substrate and / or the pores of the substrate can be filled with the composition.

[0104] In certain embodiments, the composition may comprise a specified weight of total catalyst. In certain embodiments, the total support composition or dispersion may be from about 10% to about 150% by weight of the total catalyst weight, or any amount therebetween. In certain further embodiments, the total support composition or dispersion may be from about 40% to about 60% by weight of the total catalyst weight. As used herein, "total support composition" or "total support dispersion" may refer to the amount by weight of the composition applied, coated, or supported on a substrate or support material to provide the catalyst. "Total catalyst weight" may refer to the weight of any combination of elements in the catalyst, including, but not limited to, the composition, support material, substrate, rare earth elements, dopants, and / or precious metals in the catalyst. In certain embodiments, the composition may be applied to a substrate at a weight loading of greater than 0% to about 300%, as desired to achieve a desired mixed metal oxide composition or catalyst. The total support composition applied or coated on the substrate may be modified by varying the ratio of starting metal materials and solvent levels to obtain a desired total support composition. In certain embodiments, the total supported composition applied or coated on the substrate can be modified by repeating the steps of applying, removing and calcining to obtain the desired total supported catalyst.

[0105] Those skilled in the art will understand that the function of a catalyst, such as a catalyst used in an engine, including an internal combustion engine, can depend on the temperature at which catalysis occurs. Catalysts, such as those present in an internal combustion engine, can include a reaction initialization temperature and an operating temperature. The reaction initialization temperature may refer to the temperature at which a catalytic reaction begins or begins at a significant rate. Those skilled in the art will understand that some catalysts, such as those used in internal combustion engines, can have a high reaction initialization temperature, e.g., greater than 350°C. A lower reaction initialization temperature can result in the onset of catalytic activity sooner than a catalyst having a higher reaction initialization temperature; as a result, a catalyst having a lower reaction initialization temperature can initiate catalytic activity sooner, provide a longer period of catalytic activity, and convert a higher percentage of harmful emissions into less harmful emissions. In certain embodiments, a catalyst or composition can have a reaction initialization temperature below about 400°C, below about 350°C, below about 300°C, or below about 250°C. Operating temperature, as used herein, can refer to the temperature at which a catalyst substantially operates after reaching or exceeding the reaction initialization temperature or light-off temperature. The use of lower operating temperatures may improve one or more properties of the catalyst, including, but not limited to, increased stability, extended life, and increased emission reductions. In certain embodiments, the operating temperature of the catalyst or composition may be from about 300°C to about 700°C.

[0106] In certain embodiments described herein, the catalyst may be used in a catalytic converter. As used herein, a "catalytic converter" refers to a device that converts NO from an engine, such as an internal combustion engine, into a catalytic converter. XA catalytic converter is an emission control device that converts toxic gases, such as pollutants including NOx, CO, and hydrocarbons, into less harmful products. A catalytic converter may function by catalyzing oxidation and / or reduction reactions with toxic gases to increase the formation of less harmful products. In certain embodiments, the catalytic converter may be a three-way catalytic converter, which may control emissions of NOx, CO, and hydrocarbons within a single catalytic converter. In certain embodiments, the catalytic converter may include one or more zones of catalysis, or it is contemplated that catalysis may occur within one or more catalytic converters described herein operably connected to an internal combustion engine.

[0107] It is contemplated that in certain embodiments, the catalyst may have a substantially improved ability to reduce harmful emissions over a range of lambda values. As used herein, "lambda" or "lambda value" may refer to the air-to-fuel ratio, where a value of 1 may represent stoichiometry, the correct amount of air (or oxygen) present to combust the fuel. Values ​​greater than 1 may indicate an excess of air (or oxygen), and values ​​less than 1 may indicate an excess of fuel. In various embodiments, the catalysts or compositions described herein may provide a NOx reduction that is comparable to the low NOx reduction achieved by prior art catalysts. X Lambda values ​​between 0.995 and 0.998, which is a range that indicates conversion, can be used. In certain embodiments, the mixed metal oxide catalysts produce higher levels of NO than other technologies known in the art. X In certain embodiments, the mixed metal oxide catalysts may reduce NO emissions to a greater extent than other technologies known in the art. X In certain embodiments, the mixed metal oxide catalysts can reduce NO levels to a greater extent than other technologies known in the art across a range of lambda values. X In certain embodiments, the mixed metal oxide compositions may reduce NOx, CO, and HC levels to a greater extent than other technologies known in the art across a range of lambda values.

[0108] Oxidation reactions, such as those that convert CO and hydrocarbons to less harmful emissions in catalytic converters, can proceed substantially more efficiently at lean fuel conditions or lambda values ​​greater than 1. For rich fuel conditions or lambda values ​​less than 1, NO X The catalysis of reduction reactions, such as the conversion of methyl methyl ketone to nitrogen, can be improved through the use of the catalysts or compositions described herein.

[0109] method In various embodiments, provided herein are methods for removing one or more contaminants from a gas stream, comprising exposing the gas stream to a mixed metal oxide catalyst described herein. As used herein, the term "remove" may refer to the complete removal of one or more contaminants, a substantial reduction of one or more contaminants, or a substantial reduction of one or more contaminants compared to conventional catalysts, compositions, or technologies. As used herein, the term "pollutant" may include any toxic or harmful emissions resulting from the operation or use of a technology or machine, such as an engine. In certain embodiments, pollutants may include emissions, toxic emissions, harmful emissions, or any equivalent term known to those skilled in the art in light of the teachings herein. Pollutants include NOx, ... X The term "gas stream," as used herein, may refer to a continuous flow of gases input or output during the combustion of a fuel to generate energy. In certain embodiments, the gas stream may include a gas stream, an exhaust gas stream, a flue gas stream, a diesel stream, a kerosene stream, or any combination thereof. In light of the teachings herein, one skilled in the art will be able to select an appropriate method of exposing the gas stream to a catalyst, including, but not limited to, passing the gas stream through a catalytic converter. Increasing the area of ​​the catalytic converter to which the gas stream is exposed may improve the reduction of harmful pollutants.

[0110] In certain embodiments, the gas stream can be exposed to the catalyst at an operating temperature. In certain embodiments, exposing the gas stream to the composition or catalyst can occur at an operating temperature of about 300° C. to about 700° C. Performing the method at a lower operating temperature can improve properties such as the stability or lifetime of the composition or catalyst.

[0111] In certain embodiments, the reaction initiation temperature for catalytic action of the catalyst may be less than about 350° C. In various embodiments, carrying out the method with a catalyst having a lower reaction initiation temperature may have advantages over carrying out the method with a catalyst or composition comprising a higher reaction initiation temperature, as described above.

[0112] process Reference will now be made in detail to exemplary embodiments of the present disclosure, wherein like numerals refer to like elements, examples of which are illustrated in the accompanying drawings which further illustrate, without limitation, exemplary embodiments.

[0113] In one embodiment, as shown in FIG. 4 , a process for preparing a mixed metal oxide catalyst includes: (a) preparing a dispersion comprising a metal solution 102, which may include a solvent and aluminum, copper, and cobalt in solution, and the total concentration of metal ions in the solution may be from about 0.5 M to about 5 M; (b) applying the dispersion to a substrate 104; (c) removing the solvent from the substrate to form a catalyst precursor 106; and (d) calcining the catalyst precursor to produce a catalyst 108, wherein the catalyst comprises an elemental ratio of aluminum to cobalt to copper of X:Y:1, where X may be in the range of about 1 to about 80 and Y may be in the range of about 1 to about 39. Provided herein is a process comprising:

[0114] As described herein, the dispersion comprises a solution containing metal ions. In certain embodiments, the solution may comprise a washcoat. The metal ions may be prepared by mixing with or dissolving in a solvent. In light of the teachings herein, one skilled in the art will be able to select an appropriate solvent for the metal-containing compounds or chemicals for the preparation of the catalysts described herein. In certain embodiments, the solvent may comprise water and / or acetone.

[0115] In certain embodiments, the total concentration of metal ions in a solution can be about 0.5 M to about 5 M, or any amount therebetween. In certain further embodiments, the total concentration of metal ions in a solution can be about 1 M to about 3 M, about 1.5 M to about 2.5 M, or about 1.7 M to about 2.3 M. As used herein, "total concentration of metal ions" can refer to the combined concentration of each metal ion in a solution; for example, a solution containing about 0.5 M each of copper, aluminum, and cobalt would comprise a 1.5 M metal solution. In certain embodiments, the concentration of metal ions in a solution can substantially correspond to the final desired ratio and / or weight loading of the elements in a mixed metal oxide composition or catalyst. In certain embodiments, the total concentration of metal ions in a solution can be substantially different from the desired ratio and / or weight loading of the elements in a mixed metal oxide catalyst. In certain embodiments, the concentration of one or more metal ions in a solution can be substantially different from the desired ratio and / or weight loading, and the concentration of one or more metal ions in a solution can substantially correspond to the desired ratio and / or weight loading. However, very low metal ion concentrations may not produce catalysts with sufficient capacity to perform catalytic reactions to reduce harmful emissions because the catalyst may not have a sufficient amount of metal oxide to perform oxidation and reduction reactions. Furthermore, continuous repetition of the process using low-concentration metal ion solutions may result in undesirable effects such as impurities and loss of stability if repeated too many times. Using high concentrations of metal ions may result in supersaturated solutions that may not be uniformly dispersed, coated, or applied to form a catalyst. The use of high concentrations of metal ions may also increase the production costs of the catalyst.

[0116] In certain embodiments, applying the dispersion to the substrate 104 may include any known technique for applying the metal solutions described herein to the substrates described herein, such as, but not limited to, dipping, painting, or spraying.

[0117] In certain embodiments, removing the solvent from the substrate 106 to form a catalyst precursor may include evaporating the solvent. In certain embodiments, removing the solvent from the substrate 106 may include drying or evaporating the solvent so that the solvent is substantially absent from the substrate. Those skilled in the art will understand, in light of the teachings herein, that high evaporation temperatures may cause premature oxidation, such as oxidation of the copper precursor, which may affect the uniform distribution of the precursor or the formation of the desired composition or catalyst. Depending on the elements, or amounts of elements, present in the composition or catalyst, removing the solvent from the substrate 106 may require specific parameters to produce the desired composition and / or catalyst.

[0118] The catalyst precursors described herein are compositions containing the desired metal ion(s) before being converted by calcination to produce a mixed metal oxide catalyst.

[0119] As used herein, the term "calcination" may refer to a thermal process in which materials may be pyrolyzed and / or volatile fractions may be removed. In certain embodiments, calcining the catalyst precursor to produce the catalyst 108 may be performed in air or in the presence of oxygen. In certain embodiments, calcining the catalyst precursor to produce the catalyst 108 may be performed at a temperature sufficient to obtain a mixed oxide catalyst with the desired ratio. In certain embodiments, calcining the catalyst precursor to produce the catalyst 108 may include a temperature of about 800°C to about 1000°C. In certain embodiments, calcining the catalyst precursor to produce the catalyst 108 may include a temperature of about 800°C to about 900°C. Calcination at higher temperatures, for example, above 1000°C, may result in the formation of undesired phases, which may not produce a spinel oxide with the desired ratio of metal oxides. Calcining the catalyst precursor to produce the catalyst 108 may be performed in any manner that produces a mixed metal oxide catalyst with the desired ratio. In light of the teachings herein, one skilled in the art will be able to select an appropriate technique for calcining a catalyst precursor to produce a catalyst 108 that can minimize undesirable side effects such as phase separation.

[0120] In certain embodiments, each metal oxide in the mixed metal oxide composition or catalyst can be prepared independently using a salt, oxide, or organometallic containing the desired metal cation. In certain embodiments, the mixed metal oxide composition or catalyst can be prepared using a metal salt. In certain embodiments, the metal salt can be a nitrate, chloride, acetate, any other soluble metal complex, or a combination thereof. In certain embodiments, the desired ratio of mixed metal oxides in the composition or catalyst can be produced using solid-phase synthesis methods, processes, or techniques known to those skilled in the art, including, but not limited to, combining oxides of the metals in the desired ratio.

[0121] In certain embodiments, the steps of applying the dispersion to the substrate 104, removing the solvent to produce the catalyst precursor 106, and calcining the catalyst precursor to produce the catalyst 108 may be repeated one or more times to produce the catalyst 110, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 times. In certain embodiments, applying the dispersion to the substrate 104, removing the solvent to produce the catalyst precursor 106, and calcining the catalyst precursor to produce the catalyst 108 may be repeated one or more times to produce the catalyst 110 at a desired weight loading. Repeating the steps of applying the dispersion to the substrate 104, removing the solvent to produce the catalyst precursor 106, and calcining the catalyst precursor to produce the catalyst 108 multiple times may result in a loss of optimal properties of the composition or catalyst, such as a desired ratio, stability, lifespan, or emission reduction, or may result in non-optimal properties, such as impurities.

[0122] In certain embodiments, the mixed metal oxide composition and / or catalyst may include a dopant. In certain embodiments, the dopant may be added at any point in the process to achieve the desired ratio and utility of the mixed metal oxide composition and / or catalyst. In certain embodiments, the dopant may be added during the process of preparing the dispersion containing the metal solution 102. In certain embodiments, the dopant may be added to the dispersion before applying the dispersion to the substrate 104. In certain embodiments, the dopant may be added after applying the dispersion to the substrate 104.

[0123] Example The following examples illustrate features of selected embodiments, such as the preparation and properties of the mixed metal oxide compositions and catalysts described herein. The selected examples are illustrative of advantages that may be obtained compared to alternative methods; these advantages are therefore illustrative of particular embodiments and do not necessarily illustrate features of all aspects of the invention.

[0124] Preparation of mixed metal oxide catalysts A solution or washcoat of the desired Al:Co:Cu molar ratio was prepared in water containing aluminum, cobalt, and copper nitrates to produce mixed metal oxide catalysts as outlined in Table 1. A total concentration of metal ions in the metal ion solution of 1.7M to 1.8M was used. The washcoat solution was applied to a cordierite substrate, dried to remove the solvent, and calcined. The application, solvent removal, and calcination steps were repeated until the substrate contained the desired weight loading of catalyst. In this example, the samples had a catalyst coating of 40 to 90 weight percent. The cordierite substrate measured 25.4 mm long x 19 mm diameter and had a cell density of 400 cells per square inch (CPSI). [Table 1-1] [Table 1-2] [Table 1-3]

[0125] Evaluation of mixed metal oxide catalysts Catalyst evaluation was performed using a plug flow reactor with the sample inlet temperature controlled at approximately 450°C. Catalyst evaluation was performed by determining the effectiveness of the catalyst in removing harmful emissions from one or more gases by measuring the amount of gas present either before, during, or after fuel combustion in the presence of the catalyst. Gas concentrations were swept from values ​​corresponding to lean lambda to values ​​corresponding to rich lambda by scheduled changes in a set of mass flow controllers (Alicat MC / MCS series). Gas concentrations were measured using a five-gas analyzer (FGA4000XDS by Infrared Industries). Each lambda condition was held for 2.5 minutes. The procedure began at lambda 1.005 and proceeded as follows: 1.0, 0.998, 0.995, 0.99, 0.985, and 0.98. Conversion was measured using NO. X Residual NO compared to the initial concentration XCalculated based on concentration.

[0126] Gas samples were prepared and tested at various lambda values ​​by mixing the gas components and then adding 10% by volume of water to a 2 standard liters per minute (SLPM) gas flow at a total flow rate of 2.22 SLPM, for example, as shown in Table 2. [Table 2]

[0127] A compound of formula CoAl2O4 was used to prepare various mixed metal oxide compositions by substituting copper for cobalt on a mole percent basis (10%, 20%, 30%, 40%, and 50%) and used to fabricate the catalysts described above. The catalysts were tested for NO at various lambda values ​​(0.998, 0.995, and 0.99 lambda) as shown in Figure 1. X In Figure 1, element A is cobalt, element B is aluminum, and element C is copper. Figure 1 shows that catalysts made from mixed metal oxide compositions were able to convert NO X Indicates that the conversion was successful.

[0128] Formula (Cu 0.2 Co 0.8 The compound Al2O4 was used to prepare various mixed metal oxide compositions by substituting Al for cobalt on a mole percent basis (5%, 10%, 20%, and 30%) and used to fabricate the catalysts described above. The catalysts were tested for NO at various lambda values ​​(0.998, 0.995, and 0.99 lambda), as shown in Figure 2. X In Figure 2, element A is cobalt, element B is aluminum, and element C is copper. Figure 2 shows that the catalysts prepared from the mixed metal oxide compositions were able to convert NO X Indicates that the conversion was successful.

[0129] Using the catalysts in Table 1, NO X The conversion was measured and the conversion data is shown in Table 3. [Table 3-1] [Table 3-2]

[0130] A graphical representation of the data from Table 3 is shown in Figure 3. Figure 3 shows NO as a function of catalyst composition. X The conversion is shown, with each axis corresponding to the amount of aluminum, cobalt, or copper from 0 to 100%. Darker symbols in Figure 3, with square, filled triangle, and filled circle symbols, indicate lower NO X The highest NO conversion was observed compared to the same shapes with lighter shading corresponding to the compositions listed in Table 3. X The compositions listed in Table 3 have higher NO conversions. X The conversion rates are shown. For comparison, the compositions of prior art catalyst compositions are also shown in Figure 3 (marked with "x" and "donut shapes"; the shading of the symbols does not indicate relative catalytic performance) to illustrate the different compositions of prior art catalysts. The mixed metal oxide catalysts described herein have different ratios of aluminum to cobalt to copper, and exhibit lower NO conversions compared to prior art compositions. X The squares, filled circles, and filled triangles in Figure 3 correspond to compositions disclosed herein with various ratios of Al:Co:Cu (labeled Exp. I, Exp. II, and Exp. III in Figure 3).

[0131] Using a compound with an Al:Co:Cu ratio of 9:5:1, cerium was replaced by cobalt on a mole percent basis, e.g., at 0.995 lambda, as shown in Figure 5 and Table 4. X We analyzed the following: [Table 4]

[0132] A graphical representation of the data from Table 4 is shown in Figure 5. As can be seen from Figure 5, the compositions disclosed herein were effective in removing NOx from gas at 0.995 lambda. Thus, doping the mixed metal oxide compositions or catalysts disclosed herein effectively removes NOx. X The conversion rate can be further improved.

[0133] In this disclosure, all terms referred to in the singular are intended to include their plural forms. Similarly, all terms referred to in the plural are intended to include their singular forms. Furthermore, the use of "or" means "and / or" unless otherwise specified. As used herein, the term "plurality" means more than one, e.g., two or more, three or more, four or more, etc. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0134] It should be understood that compositions, catalysts, methods, and processes are described in terms of "comprising, containing, or including" various components or steps, and that compositions and methods can also "consist essentially of" or "consist of the various components and steps." Furthermore, the indefinite article "a" or "an," as used in the claims, is defined herein to mean one or more of the element it introduces.

[0135] For brevity, only certain ranges are explicitly disclosed herein. However, a range from any lower limit may be combined with any upper limit to recite a range not explicitly recited, and similarly, a range from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, and similarly, a range from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. Furthermore, whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range within that range is specifically disclosed. In particular, all value ranges disclosed herein (in the form "about a to about b" or, equivalently, "about a to b" or, equivalently, "about a to b" or, equivalently, "a to b") should be understood to represent all numbers and ranges encompassed within the broader range of values, even if not explicitly recited. Thus, every point or individual value can serve as its own lower or upper limit in combination with any other point or individual value or any other lower or upper limit to recite a range not explicitly recited.

[0136] Thus, the present disclosure is well adapted to attain the objects and advantages mentioned, as well as those inherent therein. The specific embodiments disclosed above are illustrative only, as the disclosure may be modified and implemented in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. While individual embodiments are discussed, the present disclosure covers all combinations of all such embodiments. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as set forth in the claims below. Furthermore, the terms in the claims are to have their plain and ordinary meaning unless expressly and clearly defined herein. It is therefore apparent that the specific exemplary embodiments disclosed above may be altered or modified, and all such variations are considered within the scope of the present disclosure.

[0137] Many variations of the embodiments described herein will suggest themselves to those skilled in the art in light of this disclosure, and all such variations are within the full intended scope of the appended claims.

Claims

1. 1. A mixed metal oxide catalyst comprising aluminum, cobalt, and copper, wherein the elemental ratio of aluminum to cobalt to copper is X:Y:1, where X is in the range of about 1 to about 80 and Y is in the range of about 1 to about 39, and at least a portion of said catalyst comprises a ternary spinel structure.

2. 2. The mixed metal oxide catalyst of claim 1, wherein X is in the range of about 5 to about 20 and Y is in the range of about 2 to about 19.

3. 3. The mixed metal oxide catalyst of claim 1 or 2, wherein X is in the range of about 7 to about 20 and Y is in the range of about 3 to about 15.

4. 4. The mixed metal oxide catalyst of any one of claims 1 to 3, wherein X is in the range of from about 7 to about 18, Y is in the range of from about 3 to about 13, and comprises aluminum in an amount equal to or greater than the amount of cobalt.

5. Cu ＋２ and Co ＋２ ions share the A site of the spinel structure, and Co ＋３ and Al ＋３ A mixed metal oxide catalyst according to any one of claims 1 to 4, wherein ions share the B site of the spinel structure.

6. A mixed metal oxide catalyst according to any one of claims 1 to 5, wherein the X-ray diffraction pattern does not have peaks associated with gamma alumina.

7. The mixed metal oxide catalyst of any one of claims 1 to 6, further comprising a noble metal or a rare earth element.

8. The mixed metal oxide catalyst of any one of claims 1 to 7, further comprising a dopant.

9. 9. The mixed metal oxide catalyst of claim 8, wherein the dopant is substituted with an equimolar amount of cobalt.

10. 10. The mixed metal oxide catalyst of claim 9, wherein the dopant is substituted at about 0.1% to about 20%.

11. A mixed metal oxide catalyst according to any one of claims 8 to 10, wherein the dopant comprises cerium or manganese.

12. The mixed metal oxide catalyst of any one of claims 1 to 11, further comprising a support material or substrate.

13. 13. The mixed metal oxide catalyst of claim 12, wherein the support material is uniformly dispersed in the mixed metal oxide catalyst or the mixed metal oxide catalyst is uniformly dispersed on the support material.

14. 14. The mixed metal oxide catalyst of claim 13 deposited on a base layer of said support material.

15. The mixed metal oxide catalyst of claim 12 wherein the substrate is porous.

16. 13. The mixed metal oxide catalyst of claim 12, wherein the substrate comprises cordierite, alumina, zirconia, magnesium oxide, a metal honeycomb, or a ceramic bead.

17. 17. The mixed metal oxide catalyst of any one of claims 1 to 16, wherein the catalyst has a reaction initialization temperature of less than about 350°C.

18. A method for removing one or more contaminants from a gas stream, the method comprising exposing the gas stream to a mixed metal oxide catalyst according to any one of claims 1 to 17.

19. 20. The method of claim 18, wherein the gas stream comprises an exhaust gas stream, a flue gas, a diesel exhaust, a kerosene exhaust, or any combination thereof.

20. 20. The method of claim 18 or 19, wherein the pollutants include carbon monoxide, nitrogen oxides, hydrocarbons, or any combination thereof.

21. 21. The method of any one of claims 18 to 20, wherein exposing the gas stream to the mixed metal oxide catalyst is at an operating temperature of from 300°C to 700°C.

22. 1. A process for preparing a mixed metal oxide catalyst comprising: (a) preparing a dispersion comprising a metal solution, the metal solution comprising a solvent and aluminum, copper, and cobalt in solution, the total concentration of metal ions in the solution being from about 0.5 M to about 5 M; (b) applying the dispersion to a substrate; (c) removing the solvent from the substrate to form a catalyst precursor; and (d) calcining the catalyst precursor to produce the mixed metal oxide catalyst, wherein the mixed metal oxide catalyst comprises an elemental ratio of aluminum to cobalt to copper of X:Y:1, where X is in the range of about 1 to about 80 and Y is in the range of about 1 to about 39; A process involving:

23. 23. The process of claim 22, wherein X is in the range of about 5 to about 20 and Y is in the range of about 2 to about 19.

24. 23. The process of claim 22, wherein X is in the range of about 7 to about 120 and Y is in the range of about 3 to about 15.

25. 23. The process of claim 22, wherein X is in the range of about 7 to about 18, Y is in the range of about 3 to about 13, and the amount of aluminum is equal to or greater than the amount of cobalt.

26. 26. The process of any one of claims 22 to 25, wherein the aluminum, copper, and cobalt in the metal solution are each independently an oxide, a salt, an organometallic complex, or any combination thereof.

27. 27. The process of claim 26, wherein the aluminum, copper and cobalt salts are aluminum nitrate, copper nitrate and cobalt nitrate.

28. The process of any one of claims 22 to 27, further comprising adding a support material.

29. 30. The process of claim 28, wherein the support material is added to the dispersion during step (a).

30. The process of any one of claims 22 to 29, wherein applying the dispersion to the substrate comprises distributing the dispersion evenly on the substrate.

31. The process of any one of claims 22 to 29, wherein said applying comprises dipping said substrate into said dispersion.

32. The process of any one of claims 22 to 31, wherein the solvent comprises water or acetone.

33. The process of any one of claims 22 to 32, wherein the total supported dispersion is from 10% to 150% by weight of the total weight of the mixed metal oxide catalyst.

34. The process of any one of claims 22 to 32, wherein the total supported dispersion is from 40% to 60% by weight of the total weight of the mixed metal oxide catalyst.

35. The process of any one of claims 22 to 34, wherein firing the composition comprises heating at a temperature of from about 800°C to about 1000°C for from about 10 minutes to about 60 minutes.

36. 36. The process of any one of claims 22 to 35, wherein steps (b) to (d) are repeated one or more times to produce the catalyst.

Images