Abstract: Described is a nitrogen oxide storage catalyst comprising: a substrate; a first washcoat layer provided on the substrate, the first washcoat layer comprising a nitrogen oxide storage material, a second washcoat layer provided on the first washcoat layer, the second washcoat layer comprising a hydrocarbon trap material, wherein the hydrocarbon trap material comprises substantially no element or compound in a state in which it is capable of catalyzing selective catalytic reduction, preferably wherein the hydrocarbon trap material comprises substantially no element or compound in a state in which it is capable of catalyzing a reaction wherein nitrogen oxide is reduced to N2, said catalyst further comprising a nitrogen oxide conversion material which is either comprised in the second washcoat layer and/or in a washcoat layer provided between the first washcoat layer and the second washcoat layer.

Abstract: A method for providing a catalyst on a substrate is disclosed comprising providing a first washcoat comprising a soluble washcoat salt species, a polar organic solvent, and an insoluble particulate material, contacting the first washcoat with a substrate to form a coated substrate, and then contacting the coated substrate with a second washcoat comprising an oxide or an oxide-supported catalyst to physisorb, chemisorb, bond, or otherwise adhere the oxide or the oxide-supported catalyst to the coated substrate. Also disclosed is a catalyst on a substrate comprising: a substrate; an anchor layer comprising a soluble washcoat salt species, a polar organic solvent, and an insoluble particulate material; and a second layer comprises an oxide or an oxide-supported catalyst. The catalyst on a substrate can be in either green or fired form.

Abstract: A catalyst support body containing an SiO2-containing material and a metal selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals and mixtures thereof, wherein the total metal content lies in the range of from 0.5 to 10 wt.-%, relative to the total weight of the catalyst support. Also, a catalyst that comprises a catalyst support body according to the invention and a catalytically active metal, in particular palladium and/or gold. Also, a method for producing a catalyst support, wherein an SiO2-containing material is treated with a metal-containing compound, dried and then calcined. Also, a method for producing a catalyst, in which a solution having a precursor compound of a catalytically active metal is applied to a catalyst support body.

Abstract: A catalytic article for decomposition of a volatile organic compound includes a porous support body, a plurality of active centers formed on the support body and adapted for catalytic decomposition of the volatile organic compound, and a plurality of capture centers bound to the support body. Each of the active centers is composed of one of a noble metal, a transition metal oxide, and the combination thereof. Each of the capture centers includes at least one functional group that is adapted for attracting or binding the volatile organic compound. A method for preparing the catalytic article is also disclosed.

Abstract: The invention relates to a method of production of catalyst particles, comprising platinum and tin and also at least one further element, selected from lanthanum and cesium, on zirconium dioxide as support, comprising the steps: preparation of one or more solutions containing precursor compounds of Pt, Sn and at least one further element of La or Cs and also ZrO2, converting the solution(s) to an aerosol, bringing the aerosol into a directly or indirectly heated pyrolysis zone, carrying out pyrolysis, and separation of the particles formed from the pyrolysis gas. Suitable precursor compounds comprise zirconium(IV) acetylacetonate, lanthanum(II) acetylacetonate and cesium acetate, hexamethyldisiloxane, tin 2-ethylhexanoate, platinum acetylacetonate, zirconium(IV) propylate in n-propanol and lanthanum(II) acetylacetonate. The invention also relates to the catalyst particles obtainable using the method according to the invention, and to the use thereof as dehydrogenation catalysts.

Abstract: A method of making a metal oxide nanoparticle comprising contacting an aqueous solution of a metal salt with an oxidant. The method is safe, environmentally benign, and uses readily available precursors. The size of the nanoparticles, which can be as small as 1 nm or smaller, can be controlled by selecting appropriate conditions. The method is compatible with biologically derived scaffolds, such as virus particles chosen to bind a desired material. The resulting nanoparticles can be porous and provide advantageous properties as a catalyst.

Abstract: The present invention relates to the use of atomic layer deposition (ALD) techniques to enhance the acid catalytic activity of nanoporous materials.

Abstract: Described is a product comprising an amount of particles having one or more multi-layered dots on their surface, each multi-layered dot consisting of two or more layers and having an innermost layer contacting the surface of the particle, and an outermost layer, wherein the innermost layer of the multi-layered dots consists of a first metal and the outermost layer of the multi-layered dots consists of a second metal, different from the first metal.

Abstract: The present invention provides a process for making regular shaped particles of solid foam. A first mixture, comprising water, an acid, a surfactant and a hydrophobic material, is combined with a hydrolysable silicon species to form a second mixture. The second mixture is maintained under conditions and for a sufficient time to form regular shaped precursor particles. The second mixture is then aged at a temperature and for a time effective to produce the regular shaped particles of solid foam.

Abstract: A metal compound catalyst is formed by vaporizing a quantity of catalyst material and a quantity of carrier thereby forming a vapor cloud, exposing the vapor cloud to a co-reactant and quenching the vapor cloud. The nanoparticles are impregnated onto supports. The supports are able to be used in existing heterogeneous catalysis systems. A system for forming metal compound catalysts comprises means for vaporizing a quantity of catalyst material and a quantity of carrier, quenching the resulting vapor cloud, forming precipitate nanoparticles comprising a portion of catalyst material and a portion of carrier, and subjecting the nanoparticles to a co-reactant. The system further comprises means for impregnating the of supports with the nanoparticles.

Abstract: A CO2 reforming catalyst composition includes a hydroxyl group-containing porous oxide, and a composite porous catalyst supported by a porous supporter. The composite porous catalyst includes a catalyst metal.

Abstract: The present invention provides for a composition comprising a nanostructured transition metal oxide capable of oxidizing two H2O molecules to obtain four protons. In some embodiments of the invention, the composition further comprises a porous matrix wherein the nanocluster of the transition metal oxide is embedded on and/or in the porous matrix.

Abstract: Provided is an inexpensive material having a photocatalytic action. A photocatalyst is obtained by halogenation-treating glass fibers containing silicon dioxide in its components. Fused quartz, soda-lime glass, non-alkali glass, and borosilicate glass may be used for the glass. Hydrofluoric acid, hydrochloric acid and hydrobromic acid may be used for the halogen acid, and hydrofluoric acid is most desirable. The glass can be particulate, fibrous or sheet form material. The glass exhibits a photocatalytic action even with visible light other than ultraviolet light, and also water repellent effect. The glass according to the invention is capable of decomposing organic substances, and therefore, it is used for window glass in buildings or in transportation such as automobiles, when formed in a plate shape, and for a filter in an air intake/exhaust apparatus, when formed in fibrous shape.

Abstract: The catalyst for oxidative dehydrogenation of propane to propylene includes vanadium and aluminum incorporated into the framework of a mesoporous support, viz., MCM-41, to form V—Al-MCM-41, and nickel impregnated onto the walls of the mesoporous support. Nickel loading is preferably in the range of 5 to 15% by weight of the catalyst. A process for the production of propylene from propane includes steps of placing the catalyst in a fixed bed reactor, introducing a flow of feedstock in a propane:oxygen:nitrogen ratio of about 6:6:88 by volume, maintaining the reactor at atmospheric pressure and in a temperature range of about 400 to 550° C., collecting the product, and separating propylene from the product. The process achieves propane conversion between about 6 to 22%, and a selectivity for propylene between about 22 and 70%, depending upon percent nickel content and temperature of the reaction.

Abstract: The invention relates to a method for producing micro-nano combined active systems in which nanoparticles of a first component are bonded to microparticles of a second component, comprising the following steps: (a) producing a low-ligand colloidal suspension containing nanoparticles of the first component, (b) adding microparticles to the colloidal suspension containing the nanoparticles or adding the colloidal suspension containing the nanoparticles to a dispersion containing the microparticles and intensively mixing so that the nanoparticles adsorb onto the microparticles, (c) separating the microparticles and the nanoparticles bonded thereto from the liquid and drying the microparticles and the nanoparticles bonded thereto.

Abstract: Zero valent metal composite, manufacturing thereof, using thereof, and system including thereof, for (in-situ or ex-situ) catalytically treating contaminated water, such as sub-surface water, surface water, above-surface water, water vapor, or/and gaseous water. Composite includes powdered diatomite matrix incorporated with nanometer (1-1000 nm) sized particles of a zero valent (transition) metal (iron, cobalt, nickel, copper, zinc, palladium, platinum, or/and gold) and at least one electron transfer mediator (catalyst) from porphyrinogenic organometallic complexes (e.g., metalloporphyrins (chlorophylls, hemes, cytochromes) or metallocorrins (e.g., vitamin B12), and optionally, includes vermiculite. System includes composite and in-situ or/and ex-situ unit containing the composite, enabling exposure of contaminated water thereto. Applicable to in-situ sub-surface permeable reactive barriers (PRBs).

Abstract: According to various embodiments, a catalyst composition includes a catalytic metal secured to a porous substrate. The substrate has pores that are templated. The substrate is a product of adding a substrate precursor to a water-in-oil microemulsion including a catalytic metal salt, a solvent, a templating agent, and water.

Abstract: Catalysts and processes for forming catalysts for use in hydrogenating acetic acid to form ethanol. In one embodiment, the catalyst comprises a first metal, a silicaceous support, and at least one metasilicate support modifier. Preferably, the first metal is selected from the group consisting of copper, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum, titanium, zinc, chromium, rhenium, molybdenum, and tungsten. In addition the catalyst may comprise a second metal preferably selected from the group consisting of copper, molybdenum, tin, chromium, iron, cobalt, vanadium, tungsten, palladium, platinum, lanthanum, cerium, manganese, ruthenium, rhenium, gold, and nickel.

Abstract: The present invention relates to a catalyst-containing nanofiber composition, comprising a ceramic nanofiber having a plurality of metal catalysts wherein the metal catalysts exist as dispersed particles partially embedded in the nanofiber and cover from about 1% to about 90% of the surface area of the ceramic nanofiber.

Abstract: A composition comprising an extruded inorganic support comprising an oxide of a metal or metalloid, and at least one catalytically active metal, wherein the extruded inorganic support has pores, a total pore volume, and a pore size distribution, wherein the pore size distribution displays at least two peaks of pore diameters, each peak having a maximum, wherein a first peak has a first maximum of pore diameters of equal to or greater than about 120 nm and a second peak has a second maximum of pore diameters of less than about 120 nm, and wherein greater than or equal to about 5% of a total pore volume of the extruded inorganic support is contained within the first peak of pore diameters.

Abstract: A catalyst composition is provided that includes a catalytic metal secured to a substrate, and the substrate is mesoporous and has pores that are templated. A catalyst composition includes a catalytic metal secured to a mesoporous substrate. The mesoporous substrate is a reaction product of a reactive solution, a solvent, a modifier, and a templating agent. A method includes reacting a reactive solution and a templating agent to form a gel; and calcining the gel to form a substrate having a mesoporous template that is capable to support a catalyst composition.

Abstract: Catalysts are disclosed comprising fibrous substrates having silica-containing fibers with diameters generally from about 1 to about 50 microns, which act effectively as “micro cylinders.” Such catalysts can dramatically improve physical surface area, for example per unit length of a reactor or reaction zone. At least a portion of the silica, originally present in the silica-containing fibers of a fibrous material used to form the fibrous substrate, is converted to a zeolite (e.g., having a SiO2/Al2O3 ratio of at least about 150) that remains deposited on these fibers. The fibrous substrates possess important properties, for example in terms of acidity, which are useful in hydroprocessing (e.g., hydrotreating or hydrocracking) applications.

Abstract: A method of forming a Fischer-Tropsch catalyst by providing at least one metal nitrate solution, combining each of the at least one metal nitrate solutions with a precipitating agent whereby at least one catalyst precipitate is formed, and incorporating a strong base during precipitation, subsequent precipitation, or both during and subsequent precipitation. Catalysts produced via the disclosed method are also provided.

Abstract: An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation ?0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000° C.

Abstract: Provided are improved regenerable SOx trap formulations for on-board vehicle applications. The regenerable sulfur trap formulations reduce the rate of sulfur poisoning of a downstream nitrogen storage reduction (NSR) catalyst trap in exhaust gas cleaning systems for combustion engines by adsorbing SOx as metal sulfate under lean exhaust conditions and desorbing the accumulated SOx under rich exhaust conditions. The regenerable sulfur oxides trap catalyst compositions include a metal (M) oxide, wherein M is selected from Cu, Fe, Mn, Ag, Co and combinations thereof and a metal (M)-La—Zr oxide, wherein M is selected from Cu, Fe, Mn, Ag, Co and combinations thereof. In addition, provided are improved exhaust gas cleaning systems and methods for treating exhaust gas from a combustion source that include a hydrogen generation system, a regenerable sulfur oxides trap, and a regenerable nitrogen storage reduction (NSR) catalyst trap.

Abstract: The present invention relates to a method of manufacturing a heterogeneous catalyst using space specificity, comprising: depositing a metal in a core of micelles provided on a substrate; depositing an oxide around a shell of the micelles after the deposition of the metal in the core of the micelle; and reducing the metal in the core of the micelles after the deposition of the oxide, then, removing the micelles, and a method for generation of hydrogen through decomposing water in the presence of the heterogeneous catalyst prepared according to the aforesaid method under a light source.

Abstract: The present invention relates to a catalyst for hydrocarbon steam cracking for the production of light olefin, a preparation method of the catalyst and a preparation method of olefin by using the same. More precisely, the present invention relates to a composite catalyst prepared by mixing the oxide catalyst powder represented by CrZrjAkOx (0.5?j?120, 0?k?50, A is a transition metal, x is the number satisfying the condition according to valences of Cr, Zr and A, and values of j and k) and carrier powder and sintering thereof, a composite catalyst wherein the oxide catalyst is impregnated on a carrier, and a method of preparing light olefin such as ethylene and propylene by hydrocarbon steam cracking in the presence of the composite catalyst. The composite catalyst of the present invention has excellent thermal/mechanical stability in the cracking process, and has less inactivation rate by coke and significantly increases light olefin yield.

Abstract: An exhaust gas purifying catalyst (1) according to the present invention includes noble metal particles (6), a first compound (7) supporting the noble metal particles (6), and a second compound (9) disposed not in contact with the noble metal particles (6) and having an oxygen storage capacity. An average distance between the first compound (7) and the second compound (9) is between 5 nm and 300 nm.

Abstract: The present invention relates to catalysts, to processes for making catalysts with halide containing precursors and to chemical processes employing such catalysts. The catalysts are preferably used for converting acetic acid to ethanol. The catalyst comprises a precious metal and one or more active metals on a support, optionally a modified support.

Abstract: The present invention relates to catalysts, to processes for making catalysts with acidic precursors and to chemical processes employing such catalysts. The catalysts are preferably used for converting acetic acid to ethanol. The catalyst comprises a precious metal and one or more active metals on a support, optionally a modified support.

Abstract: The invention is a heteropoly acid compound catalyst composition, a method of making the catalyst composition and a process for the oxidation of saturated and/or unsaturated aldehydes to unsaturated carboxylic acids using the catalyst composition. The catalyst composition is a heteropoly acid compound containing molybdenum, vanadium, phosphorus, cesium, bismuth, copper and antimony. Thermal stability is achieved with higher cesium content (up to less than 3.0) but antimony, copper and bismuth must be present to maintain good activity. The catalyst is made by dissolving compounds of the components of each of the heteropoly acid compounds in a solution, precipitating the heteropoly acid compounds, obtaining a catalyst precursor and calcining the catalyst precursor to form a heteropoly acid compound catalyst. Unsaturated aldehydes, such as methacrolein, may be oxidized in the presence of the heteropoly acid compound catalyst to produce an unsaturated carboxylic acid, such as methacrylic acid.

Abstract: A photoactive material including nanoparticles of photoactive first and second constituents. The first and second constituents have respective conduction band energies, valence band energies and electronic band gap energies to enable photon-driven generation and separation of charge carriers in each of the first and second constituents by absorption of light in the solar spectrum. The first and second constituents are provided in an alternating layered arrangement of respective first and second layers or are mixed together in a single layer. The nanoparticles have diameters smaller than wavelengths of light in the solar spectrum, to provide optical transparency for absorption of light. The charge carriers, upon photoactivation, are able to participate in redox reactions occurring in the photoactive material. The photoactive material may enable redox reactions of carbon dioxide with at least one of hydrogen and water to produce a fuel.

Abstract: A catalyst comprising (i) a support, (ii) metal particles and (iii) a shell which is arranged between the metal particles, wherein the shell (iii) comprises silicon oxide.

Abstract: Amine stabilizing agents containing an azeotrope comprising water, an alcohol, and sodium hydride. Amine stabilizing agents containing water and a liquid silica hydroxide compound. Methods of making of amine stabilizing agents where solid silicon rock and sodium hydroxide are mixed with an ammonium/water solution to produce a green liquid in a first stage of the reaction. Alcohol is added and the alcohol fraction is separated from the non-alcohol fraction to produce an alcohol fraction product and a bottom fraction that is not soluble in alcohol or organics. The agents can be added to amines for stabilizing amines in anime processing of gases, in CO2 capture, in CO2 abatement systems and in other systems where amines are utilized to remove contaminants.

Abstract: A gas fired catalytic heater is provided that foregoes the need for an electrical heating element to provide the activation energy for the hydrocarbon catalyst pad. An alcohol self-igniting catalyst pad is used to provide the activation energy to the hydrocarbon catalyst pad thereby removing dependence of the heater on an outside electrical energy source to initiate start-up of the heater. The catalyst pad includes a flexible wash coat; a noble metal dispersed on the wash coat; an anti-sintering element saturating the wash coat; and a catalyst promoter saturating the wash coat.

Abstract: A first layer of a catalyst material is formed on a substrate and heat treated to form a first plurality of nanoparticles. A second layer of a catalyst material is then formed over the substrate and the first plurality of nanoparticles and heat treated to form a second plurality of nanoparticles. The first layer of nanoparticles is advantageously not affected by the deposition or heat treatment of the second layer of catalyst material, for example being pinned or immobilised, optionally by oxidation, before formation of the second layer.

Abstract: An exhaust gas purifying catalyst includes a monolithic substrate (2), and a transition metal oxide layer (3) formed in the monolithic substrate (2). The transition metal oxide layer (3) contains transition metal oxide powder including: transition metal oxide particles (10); a first compound (20) on which the transition metal oxide particles (10) are supported; and a second compound (30) that surrounds a single body or an aggregate of the transition metal oxide particles (10) and the first compound (20).

Abstract: The invention provides an amorphous hydrocracking catalyst for conversion of a hydrocarbon feed having a fraction above the diesel boiling range to diesel and a process using said catalyst. The catalyst includes Al203—SiO2 support, a noble catalytically active metal which is active for hydrocracking of a hydrocarbon above the diesel boiling range and a transition metal oxide selected from group V, VI and VII.

Abstract: An exhaust gas purifying catalyst (1) includes: a three-dimensional structural substrate (10) having a plurality of cells (11) partitioned by cell walls (12) having pores (13); and catalyst layers (20) formed in the three-dimensional structural substrate (10). The catalyst layers (20) have pore-cover portions (22) formed on surfaces (13a) of the pores (13) of the cell walls (12). In addition, the catalyst layers (20) of the pore-cover portions (22) have activated pores (22a) with a pore diameter of 0.1 micrometers to 10 micrometers. In the exhaust gas purifying catalyst (1), the obstruction of the vent holes (pores (13)) in the catalyst layers (20) can be controlled, and the pressure loss can be reduced.

Abstract: A catalyst which remediates hydrocarbon fuel combustion exhaust, including a non-PGM containing aerogel which catalyzes the oxidation of carbon monoxide and hydrocarbons and the reduction of nitrogen oxides present in the exhaust, a catalytic converter made therefrom, and a method for the production thereof is disclosed.

Abstract: Methods of fabricating nano-catalysts are described. In some embodiments the nano-catalyst is formed from a powder-based substrate material and is some embodiments the nano-catalyst is formed from a solid-based substrate material. In some embodiments the substrate material may include metal, ceramic, or silicon or another metalloid. The nano-catalysts typically have metal nanoparticles disposed adjacent the surface of the substrate material. The methods typically include functionalizing the surface of the substrate material with a chelating agent, such as a chemical having dissociated carboxyl functional groups (—COO), that provides an enhanced affinity for metal ions. The functionalized substrate surface may then be exposed to a chemical solution that contains metal ions. The metal ions are then bound to the substrate material and may then be reduced, such as by a stream of gas that includes hydrogen, to form metal nanoparticles adjacent the surface of the substrate.

Abstract: Zero valent metal composite, manufacturing thereof, using thereof, and system including thereof, for (in-situ or ex-situ) catalytically treating contaminated water, such as sub-surface water, surface water, above-surface water, water vapor, or/and gaseous water. Composite includes powdered diatomite matrix incorporated with nanometer (1-1000 nm) sized particles of a zero valent (transition) metal (iron, cobalt, nickel, copper, zinc, palladium, platinum, or/and gold) and at least one electron transfer mediator (catalyst) from porphyrinogenic organometallic complexes (e.g., metalloporphyrins (chlorophylls, hemes, cytochromes) or metallocorrins (e.g., vitamin B12), and optionally, includes vermiculite. System includes composite and in-situ or/and ex-situ unit containing the composite, enabling exposure of contaminated water thereto. Applicable to in-situ sub-surface permeable reactive barriers (PRBs).

Abstract: An improved redox material able to be used for thermochemical water splitting, and a method for producing hydrogen using this redox material are provided. The redox material for thermochemical water splitting comprises a redox metal oxide selected from the group comprising perovskite-type composite metal oxides, fluorite-type composite metal oxides and combinations thereof, and a metal oxide carrier. The redox metal oxide is carried on the metal oxide carrier in a dispersed state. The method for producing hydrogen uses the oxidation and reduction of the redox material to decompose water into hydrogen and oxygen.

Abstract: Compositions, materials incorporating the compositions, and methods of use thereof, for the protection and/or decontamination of contaminants are disclosed.

Abstract: A method of making a metal oxide nanoparticle comprising contacting an aqueous solution of a metal salt with an oxidant. The method is safe, environmentally benign, and uses readily available precursors. The size of the nanoparticles, which can be as small as 1 nm or smaller, can be controlled by selecting appropriate conditions. The method is compatible with biologically derived scaffolds, such as virus particles chosen to bind a desired material. The resulting nanoparticles can be porous and provide advantageous properties as a catalyst.

Abstract: Core-shell nanoparticles having a core material and a mesoporous silica shell, and a method for manufacturing the core-shell nanoparticles are provided.

Abstract: The invention involves a process for converting an oxygenate-containing feed into an olefin-containing product comprising: (a) providing a co-catalyst oxide of a metal from Groups 2-4 of the Periodic Table of Elements, Lanthanides, Actinides, and combinations thereof, (b) contacting the metal oxide with nitromethane under conditions sufficient for the nitromethane to adsorb onto the metal oxide; (c) analyzing the nitromethane-adsorbed metal oxide using NMR to determine a basic site density of the metal oxide; (d) providing a catalyst system comprising a primary catalyst comprising aluminosilicates, aluminophosphates, silicoaluminophosphates, and metal-containing derivatives and combinations thereof, and the co-catalyst metal oxide whose basic site density is ?0.

Abstract: Especially physically stable metal oxide catalyst supports are prepared by suspending a metal oxide in a continuous phase, activating by fine dispersion, coagulation to a viscoelastic mass, shaping, drying, and calcining. The catalyst support thus prepared may be treated with catalytic agents to produce supported catalysts for olefin oxidation.

Abstract: Provided is a catalyst for fuel reformation that causes carbon monoxide contained in hydrogen gas, which is produced from a variety of hydrocarbon fuels, to react with hydrogen and thereby to be transformed into methane, while inhibiting methanation of carbon dioxide contained in the hydrogen gas. The selective CO methanation catalyst includes at least one of a halogen, an inorganic acid, and a metal oxo-acid adsorbed or bonded as a carbon dioxide reaction inhibitor to a carbon monoxide methanation active component.

Abstract: It is provided that the catalyst shows a high activity in an ammonia decomposition reaction and can efficiently decompose ammonia into hydrogen and nitrogen. The catalyst for decomposing ammonia of the present invention comprises at least one element (component (A)) selected from the elements of groups 6 to 10 of the long-form periodic table, and an oxide and/or complex oxide of at least one element (component (B)) selected from the elements of groups 2 to 5 and groups 12 to 15 of the long-form periodic table, wherein the calculated specific surface area (S2) of the component (A) is 20 m2/g or larger, and the ratio (S2/S1) of the calculated specific surface area (S2) of the component (A) to the specific surface area (S1) of the catalyst per se is 0.15 to 0.85.