Abstract: Catalyst systems are provided for reforming of hydrocarbons, along with methods for using such catalyst systems. The catalyst systems can be deposited or otherwise coated on a surface or structure, such as a monolith, to achieve improved activity and/or structural stability. The metal oxide support layer can correspond to a thermally stable metal oxide support layer, such as a metal oxide support layer that is thermally phase stable at temperatures of 800° C. to 1600° C. The catalyst systems can be beneficial for use in cyclical reaction environments, such as reverse flow reactors or other types of reactors that are operated using flows in opposing directions and different times within a reaction cycle.

Abstract: A catalyst article is provided including a substrate including a plurality of passageways, and further including a first and a second oxidation region including a first and a second subset of said plurality of passageways. A first catalyst composition is coating at least a portion of each passageway of the first oxidation region and positioned as a sole PGM-containing catalyst layer, or a zoned portion thereof, or as a top PGM-containing catalyst layer, or a zoned portion thereof, in the first oxidation region. A second catalyst composition is coating at least a portion of each passageway of the second oxidation region and positioned as a sole PGM-containing catalyst layer, or a zoned portion thereof, or as a top PGM-containing catalyst layer, or a zoned portion thereof, in the second oxidation region. The Pt:Pd weight ratio is greater in the first catalyst composition than in the second catalyst composition.

Abstract: In a case where an alkali aqueous solution is used as an electrolyte, provided are an oxygen catalyst excellent in catalytic activity and composition stability, an electrode having high activity and stability using this oxygen catalyst, and an electrochemical measurement method that can evaluate the catalytic activity of the oxygen catalyst alone. The oxygen catalyst is an oxide having peaks at positions of 2?=30.07°±1.00°, 34.88°±1.00°, 50.20°±1.00°, and 59.65°±1.00° in an X-ray diffraction measurement using a CuK? ray, and having constituent elements of bismuth, ruthenium, sodium, and oxygen. An atom ratio O/Bi of oxygen to bismuth and an atom ratio O/Ru of oxygen to ruthenium are both more than 3.5.

Abstract: A hydrocarbon feed stream, particularly one comprising heavier hydrocarbons, may be converted to valuable products such as motor gasoline and/or lubricating oil by employing one or more MOF catalysts, which may be prepared from a precursor metal-organic framework (MOF). A MOF catalyst may be prepared by exchanging one or more organic linking ligands of the precursor MOF for an organic linking ligand having a different acidity and/or electron-withdrawing properties, which, in turn, may affect catalytic activity.

Abstract: A method of dry reforming of methane (CH4) is provided. The method includes contacting at a temperature of 500 to 1000 degree Celsius (° C.) a reactant gas mixture including methane and carbon dioxide (CO2) with a bimetallic supported catalyst. The bimetallic supported catalyst includes a porous catalyst support and a bimetallic catalyst. The porous catalyst support includes aluminum oxide (Al2O3) and magnesium oxide (MgO). The bimetallic catalyst includes nickel (Ni) and copper (Cu) disposed on the porous catalyst support. The method further includes collecting a product gas mixture including hydrogen (H2) and carbon monoxide (CO). The bimetallic supported catalyst includes 8 to 16 weight percent (wt. %) nickel and 2 to 14 wt. % copper, each based on a total weight of bimetallic supported catalyst.

Abstract: A method for producing a three-dimensional porous catalyst monolith of stacked catalyst fibers, comprising the following steps: a) Preparing a suspension paste in a liquid diluent of a reforming catalyst, and which suspension can furthermore comprise a binder material, all particles in the suspension having an average particle size in the range of from 0.5 to 500 ?m, b) extruding the paste of step a) through one or more nozzles to form fibers, and depositing the extruded fibers to form a three-dimensional porous catalyst monolith precursor, c) drying the porous catalyst monolith precursor to remove the liquid diluent, d) calcining the porous catalyst monolith precursor to form the porous catalyst monolith.

Abstract: Cuy/MMgOx interfacial catalyst for selective alkyne hydrogenation and its preparation method are disclosed. The preparation method of the catalyst includes: the mixture of salt and alkali solution is nucleated momentarily by nucleation/crystallization isolation method, preparing the composite metal hydroxide CuyMMg4-LDHs as precursor, which has typical hexagonal morphology of the double hydroxide; the precursor is topologically transformed by heat treatment to produce unsaturated oxide; the catalyst with Cuy-MMgOx interface structure is prepared by separating and electronically modifying Cu particles. By adjusting the ratio of Cu2+/M3+ in LDHs, the electronic and geometric structure of Cuy-MMgOx interface can be flexibly controlled, thus enhancing the reaction activity, product selectivity and stability. The catalyst can be used in the selective hydrogenation of various alkynes in the fields of petrochemical and fine chemical industry, with the outstanding catalytic activity and C?C double bond selectivity.

Abstract: A catalyst composition comprising MgO, Al2O3 and one or more further alkaline earth metal oxides, provides for outstanding catalytic production of propylene when employed together with a metathesis catalyst.

Abstract: The invention relates to a shaped catalyst body in the form of a tetralobe having four circular through-passages, with the midpoints of the through-passages forming a square and the spacings between in each case two adjacent through-passages being from 0.8 to 1.2 times the thickness of the outer walls of the through-passages. The shaped catalyst body is used for the oxidation of S02 to S03.

Abstract: The present disclosure provides an exhaust gas purification material and an exhaust gas purification device that can efficiently remove harmful components even after being exposed to high temperature. Such exhaust gas purification material comprises metal oxide particles and noble metal particles supported on the metal oxide particles. The noble metal particles have a particle size distribution with a mean of 1.5 nm and 18 nm and a standard deviation of less than 1.6 nm.

Abstract: The invention discloses a nitrogen-doped mesoporous carbon-coated Titanium dioxide composite photocatalyst, a preparation method and use thereof. The preparation method comprises the steps of: dissolving an organic ligand and Ti(OC3H7)4 in a mixture of methanol and DMF at a certain ratio, performing a hydrothermal reaction, centrifuging and drying to obtain a Titanium-based metal organic framework (Ti-MOF); pyrolyzing the obtained Ti-MOF under an inert atmosphere, and oxidizing the same for etching to obtain a nitrogen-doped mesoporous carbon-coated Titanium dioxide composite photocatalyst. The obtained composite photocatalyst not only facilitates the adsorption, enrichment and mass transfer of low concentration VOCs, but also efficiently degrades VOCs under sunlight. It has high degradation activity and stability when performing photocatalytic removal of VOCs in the presence of visible light, is simple in synthesis, low in preparation cost, and has strong potential for the use in environmental protection.

Abstract: An exhaust gas purification catalyst including particles of a catalyst metal supported on secondary particles of an inorganic oxide, wherein when scanning transmission electron microscope-energy dispersive X-ray line analysis is performed from a surface of the secondary particles toward a center thereof, a support density of the catalyst metal on a surface side of the secondary particles is greater than the support density of the catalyst metal in a center part of the secondary particles.

Abstract: Provided is a catalyst for manufacturing multi-wall carbon nanotubes, the catalyst including metal components according to <Equation> Ma:Mb=x:y, and having a hollow structure with a thickness of 0.5-10 ?m. In the above equation, Ma represents at least two metals selected from Fe, Ni, Co, Mn, Cr, Mo, V, W, Sn, and Cu; Mb represents at least one metal selected from Mg, Al, Si, and Zr; x and y each represent the molar ratio of Ma and Mb; and x+y=10, 2.0?x?7.5, and 2.5?y?8.0.

Abstract: Modified red mud catalyst compositions, methods for production, and methods of use in dry reforming, the composition comprising: red mud material produced from an alumina extraction process from bauxite ore; and nickel oxide, the nickel oxide present at between about 5 wt. % to about 40 wt. % of the modified red mud catalyst composition.

Abstract: Proposed are a low-temperature de-NOx catalyst for treating exhaust gas from a stationary source and a method of manufacturing the same. The low-temperature de-NOx catalyst can promote the reduction reaction of nitrogen oxide even at a low temperature despite supporting vanadium in a small amount, can increase resistance to sulfur poisoning, and can be easily manufactured in a manner that does not deteriorate nitrogen oxide removal efficiency even after long-term operation because it prevents secondary environmental pollution due to the treated gas and has superior abrasion resistance, thereby contributing to commercialization.

Abstract: A catalyst for dehydrogenation of hydrocarbons includes a support including zirconium oxide and alumina. A concentration of the zirconium oxide in the catalyst is in a range of from 1 weight percent (wt. %) to 20 wt. %. The catalyst includes from 0.01 wt. % to 2 wt. % of an alkali metal or alkaline earth metal. The catalyst includes from 1 wt. % to 2 wt. % of tin. The catalyst includes from 0.1 wt. % to 2 wt. % of a platinum group metal. The alkali metal or alkaline earth metal, tin, and platinum group metal are disposed on the support.

Abstract: The invention relates to a catalyst useful in the steam reforming of hydrocarbons and oxygenated hydrocarbons. The invention provides a method for preparing a catalyst comprising heating a spinel of formula ANixFe(1-X)CrO4 where A is Mn or Mg and x is from 0 to 0.75 under reducing conditions at a temperature of from 800 to 1500° C., and catalysts obtainable by said method.

Abstract: The present disclosure relates to a catalyst composite for conversion of methane gas, which includes Co3O4 nanoplates and ZrO2 nanoparticles adsorbed to the surface of the Co3O4 nanoplates, and is used for converting methane gas into alcohols, and a method for conversion of methane gas using the same. When using the catalyst composite, it is possible to convert methane gas into alcohols with high efficiency under a mild condition of room temperature and ambient pressure.

Abstract: A family of new crystalline molecular sieves designated SSZ-91 is disclosed, as are methods for making SSZ-91 and uses for SSZ-91. Molecular sieve SSZ-91 is structurally similar to sieves falling within the ZSM-48 family of molecular sieves, and is characterized as: (1) having a low degree of faulting, (2) a low aspect ratio that inhibits hydrocracking as compared to conventional ZSM-48 materials having an aspect ratio of greater than 8, and (3) is substantially phase pure.

Abstract: The present invention relates to a dehydrogenation catalyst in which a platinum-group metal, an assistant metal, and an alkali metal or alkaline earth metal component are supported on a carrier, wherein the molar ratio of platinum to the assistant metal is 0.5 to 1.49, and the catalyst has an acidity amount of 20 to 150 ?mol KOH/g catalyst when it is titrated with KOH. The dehydrogenation catalyst according to the present invention may prevent coke formation from increasing rapidly when the hydrogen/hydrocarbon ratio in a dehydrogenation reaction is reduced, thereby increasing the productivity of the process. Accordingly, it makes it possible to operate the process under a condition in which the hydrogen/hydrocarbon ratio in a dehydrogenation reaction is reduced, thereby improving the economy of the process.

Abstract: Embodiments disclosed herein relate to systems and processes for producing olefins and/or dienes. The systems and processes may include thermally cracking a C1-C4 hydrocarbon containing feed to produce a cracked hydrocarbon effluent containing a mixture of olefins and paraffins. The systems and processes may also include dehydrogenating the cracked hydrocarbon effluent to produce a dehydrogenated hydrocarbon effluent containing additional olefins and/or dienes.

Abstract: An exhaust-gas-purifying system of an internal combustion engine of the present disclosure sets a reduction treatment necessity flag to ON when an input gas temperature of an exhaust gas introduced into an exhaust-gas-purifying catalyst is higher than a reference temperature. Then, it is determined whether reduction treatment execution conditions in which the reduction treatment necessity flag has been set to ON and the input gas temperature has decreased and falls within a preset temperature range up to a reference temperature or lower are satisfied. Then, when it is determined that reduction treatment execution conditions are satisfied, a reduction treatment in which an air-fuel ratio of an intake gas supplied into the engine is adjusted to be richer than a stoichiometric air-fuel ratio is performed, and the reduction treatment necessity flag is set to OFF.

Abstract: A NOx trap catalyst is disclosed. The NOx trap catalyst comprises a noble metal, a NOx storage component, a support, and a first ceria-containing material. The first ceria-containing material is pre-aged prior to incorporation into the NOx trap catalyst, and may have a surface area of less than 80 m2/g. The invention also includes exhaust systems comprising the NOx trap catalyst, and a method for treating exhaust gas utilizing the NOx trap catalyst.

Abstract: An exhaust gas-purifying catalyst of the present invention comprises a substrate, and one or more catalytic layers provided on the substrate, wherein at least one of the catalytic layers (i) contains a precious metal, alumina, and an acidic oxide element, (ii) has a correlation coefficient ?Al,AE of 0.70 or more, and (iii) has a correlation coefficient ?PM,AE of 0.70 or more.

Abstract: Provided is a Group 9 novel metal catalyst complex further comprising a ketone-containing cocatalyst. The metal catalyst complex is useful in generating olefins from alkanes with great efficiency. In one embodiment, provided is an iridium catalyst complex useful in the dehydrogenation of alkanes comprising a ketone-containing cocatalyst and iridium complexed with a tridentate ligand. Also provided is a novel dehydrogenation method which utilizes the catalyst composition. In other embodiments, a novel process for preparing oligomers from alkanes utilizing the catalyst composition is provided.

Abstract: In a broad form the present invention relates to a method for oxidation of a species comprising sulfur in an oxidation state below +4, such as H2S, CS2, COS and S8 vapor, to SO2 said method comprising the step of contacting the gas and an oxidant with a catalytically active material consisting of one or more elements taken from the group consisting of V, W, Ce, Mo, Fe, Ca, Mg, Si, Ti and Al in elemental, oxide, carbide or sulfide form, optionally with the presence of other elements in a concentration below 1 wt %, at a temperature between 180° C. and 290° C., 330° C., 360° C. or 450° C., with the associated benefit of such a temperature being highly energy effective, and the benefit of said elements having a low tendency to form sulfates under the conditions, with the related benefit of an increased stability of the catalytically active material. The other elements present may be catalytically active noble metals or impurities in the listed materials.

Abstract: Provided is a Group 9 novel metal catalyst complex further comprising a ketone-containing cocatalyst. The metal catalyst complex is useful in generating olefins from alkanes with great efficiency. In one embodiment, provided is an iridium catalyst complex useful in the dehydrogenation of alkanes comprising a ketone-containing cocatalyst and iridium complexed with a tridentate ligand. Also provided is a novel dehydrogenation method which utilizes the catalyst composition. In other embodiments, a novel process for preparing oligomers from alkanes utilizing the catalyst composition is provided.

Abstract: Methods and systems for producing and removing C6 and/or C8 carboxylates and/or methane from carbohydrate containing biomass, an alcohol, and mixtures of microorganisms under an anaerobic environment. The C6 and/or C8 carboxylates are removed continuously or in-line. Methanogenesis is not inhibited and very little input carbon is lost as carbon dioxide.

Abstract: Rapid, reversible redox activity may be accomplished at significantly reduced temperatures, as low as about 200° C., from epitaxially stabilized, oxygen vacancy ordered SrCoO2.5 and thermodynamically unfavorable perovskite SrCoO3-?. The fast, low temperature redox activity in SrCoO3-? may be attributed to a small Gibbs free energy difference between the two topotactic phases. Epitaxially stabilized thin films of strontium cobaltite provide a catalyst adapted to rapidly transition between oxidation states at substantially low temperatures. Methods of transitioning a strontium cobaltite catalyst from a first oxidation state to a second oxidation state are described.

Abstract: The disclosure provides catalyst materials useful for hydrogenating olefins and shifting carbon monoxide and methods for using such catalyst materials. In one aspect, the disclosure provides catalyst materials including (a) copper, present in the range of about 20 weight % to about 80 weight %; (b) one or more stabilizer oxides stable under reducing conditions, each stabilizer oxide being a transition metal oxide or a metalloid oxide, the one or more stabilizer oxides being present in a total amount in the range of about 20 weight % to about 70 weight %; and (c) one or more multiple-valence metals, each multiple-valence metal being present in a positive oxidation state, the one or more multiple-valence metals are present in the range of about 0.1 weight % to about 40 weight %, all on an oxide basis.

Abstract: The present invention relates to a process for hydrogenation of olefinic or acetylenic bonds. Further, the present invention relates to a process for selective hydrogenation of olefinic or acetylenic bonds and/including triglycerides using modified metal supported on solid acidic metal oxide catalyst and the process for the preparation thereof. The present invention provides a process for hydrogenation of olefinic or acetylenic bonds using metal supported on solid acid metal oxide based catalyst, at moderate conditions. The present invention also relates to the preparation of metal supported on solid acid metal oxide based catalyst for hydrogenation reactions under mild conditions.

Abstract: The present invention relates to a process for producing a catalyst for the reforming of hydrocarbons, preferably methane, in the presence of CO2, water and/or hydrogen. The production of the catalyst is based on contacting of a hydrotalcite-comprising starting material with a fusible metal salt. The compounds which have been brought into contact with one another are intimately mixed and treated thermally, resulting in the fusible metal salt forming a melt. After molding, the material is subjected to a high-temperature calcination step. The metal salt melt comprises at least one metal selected from the group consisting of K, La, Fe, Co, Ni, Cu and Ce, preferably Ni. The metal salt melt more preferably comprises nickel nitrate hexahydrate.

Abstract: The purpose of the present invention is to provide an oxidation catalyst for exhaust gas purification having high durability and a method for producing the catalyst. The purpose is achieved by an oxidation catalyst for exhaust gas purification containing a refractory inorganic oxide, and a catalyst component and a metal component, which are supported on the refractory inorganic oxide, wherein the catalyst component is platinum, or platinum and palladium, and the metal component is one or more selected from the group consisting of magnesium, calcium, strontium and barium.

Abstract: A catalyst includes an olivine substrate on which an iron compound layer is deposited, produced by impregnating the olivine substrate with a solution including an iron salt, and then heat-treating. The catalyst is useful for steam-reforming tar, in particular in gaseous media from the steam gasification of biomass. Further, the catalyst can be used alone for catalyzing the steam gasification of organic compounds from biomass while limiting the amount of tar produced in the synthesized gases.

Abstract: Disclosed is an exhaust gas purifying catalyst which includes barium hexaaluminate, and palladium and barium which are supported on barium hexaaluminate, wherein the amount of supported palladium, as reduced to metallic Pd, is 0.2 to 3.5 mass % with respect to the mass of barium hexaaluminate; the amount of supported barium, as reduced to BaO, is 1 to 20 mass % with respect to the mass of barium hexaaluminate; and the ratio by mole of supported barium to supported palladium, Ba/Pd, is (0.5 to 10)/1; an exhaust gas purifying catalyst product which has a catalyst support made of a ceramic or metallic material, and a layer which is formed of the exhaust gas purifying catalyst as a predominant component and which is supported on the catalyst support; and a method for producing the exhaust gas purifying catalyst product.

Abstract: A method for regenerating deactivated ionic liquid catalyst containing conjunct polymer. The deactivated ionic liquid catalyst containing the conjunct polymer is contacted with either at least one metal complex having a general formula M1n+Rn, or at least one metal complex having a general formula [M2a+]x[M3b+yRz](xa/(z?by)). The conjunct polymer reacts with the reagent and can be extracted from the ionic liquid. The mixture is separated into a hydrocarbon effluent and an ionic liquid effluent.

Abstract: The present invention relates to a provides a catalyst comprising (a) a solid support comprising an alkaline earth metal oxide, fluoride, or oxyfluoride, and (b) at least one elemental metal disposed on or within said support, preferably wherein said elemental metal is present in an amount from about 0.01 to about 10 weight percent based upon the total weight of the metal and support. It also relates to the use of the catalyst for the dehydrochlorination of a hydrochlorofluorocarbon.

Abstract: A one-layer three-way catalyst is described for the cleaning of the exhaust gases of internal combustion engines with outstanding activity and thermal stability. The catalyst comprises an active aluminum oxide, a first cerium/zirconium mixed oxide and a second cerium/zirconium mixed oxide. The first cerium/zirconium mixed oxide has a higher zirconium oxide content than the second mixed oxide. The first cerium/zirconium mixed oxide is catalytically activated with rhodium and the second cerium/zirconium mixed oxide with palladium.

Abstract: The present invention provides a catalyst for forming carbon nanotubes that improves a yield at the time of manufacturing carbon nanotubes and enables continuous mass production of carbon nanotubes with high purity. The catalyst for forming carbon nanotubes of the present invention includes a carrier that includes MgO and a metal catalyst that is supported by the carrier, and the concentration of the MgO in the carrier is set equal to 99 mass % or higher.

Abstract: Rapid, reversible redox activity may be accomplished at significantly reduced temperatures, as low as about 200° C., from epitaxially stabilized, oxygen vacancy ordered SrCoO2.5 and thermodynamically unfavorable perovskite SrCoO3-?. The fast, low temperature redox activity in SrCoO3-? may be attributed to a small Gibbs free energy difference between the two topotactic phases. Epitaxially stabilized thin films of strontium cobaltite provide a catalyst adapted to rapidly transition between oxidation states at substantially low temperatures. Methods of transitioning a strontium cobaltite catalyst from a first oxidation state to a second oxidation state are described.

Abstract: The present invention relates to a process for obtaining metal oxide catalysts comprising gallium which are capable of synthesising higher alcohols from lower alcohols. The process for obtaining said catalysts is also disclosed.

Abstract: A method for preparing an improved slurry catalyst for the upgrade of heavy oil feedstock is provided. In one embodiment, the process comprises: sulfiding at least a metal precursor solution with at least a sulfiding agent forming a sulfided Group VIB catalyst precursor, the metal precursor solution having a pH of at least 4 and a concentration of less than 10 wt. % of Primary metal in solution; and mixing the catalyst precursor with a hydrocarbon diluent to form the slurry catalyst composition. The slurry catalyst prepared therefrom has a BET total surface area of at least 100 m2/g, a total pore volume of at least 0.5 cc/g and a polymodal pore distribution with at least 80% of pore sizes in the range of 5 to 2,000 Angstroms in diameter.

Abstract: A process for making an improved slurry catalyst for the upgrade of heavy oil feedstock is provided. In the process, a metal precursor solution comprising at least a water-soluble molybdenum compound and a water-soluble metal zinc compound is mixed under high shear mixing conditions to generate an emulsion. The emulsion is subsequently sulfided with a sulfiding agent ex-situ, or in-situ in a heavy oil feedstock to form the slurry catalyst. The in-situ sulfidation in heavy oil is under sufficient condition for the heavy oil feedstock to generate the sulfiding source needed for the sulfidation.

Abstract: An exhaust system for a compression ignition engine comprising an oxidation catalyst for treating carbon monoxide (CO) and hydrocarbons (HCs) in exhaust gas from the compression ignition engine, wherein the oxidation catalyst comprises: a platinum group metal (PGM) component selected from the group consisting of a platinum (Pt) component, a palladium (Pd) component and a combination thereof; an alkaline earth metal component; a support material comprising a modified alumina incorporating a heteroatom component; and a substrate, wherein the platinum group metal (PGM) component, the alkaline earth metal component and the support material are disposed on the substrate.

Abstract: A catalyst which comprises nickel and/or cobalt supported on a support that includes a mixed oxide containing metals, such as aluminum, zirconium, lanthanum, magnesium, cerium, calcium, and yttrium. Such catalysts are useful for converting carbon dioxide to carbon monoxide, and for converting methane to hydrogen.

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: A catalyst composition for converting ethanol to higher alcohols, such as butanol, is disclosed. The catalyst composition comprises at least one alkali metal, at least a second metal and a support. The second metal is selected from the group consisting of palladium, platinum, copper, nickel, and cobalt. The support is selected from the group consisting of Al2O3, ZrO2, MgO, TiO2, zeolite, ZnO, and a mixture thereof.

Abstract: Disclosed is an exhaust gas purifying catalyst in which grain growth of a noble metal particle supported on a support is suppressed. Also disclosed is a production process for producing an exhaust gas purifying catalyst. The exhaust gas purifying catalyst comprises a crystalline metal oxide support and a noble metal particle supported on the support, wherein the noble metal particle is epitaxially grown on the support, and wherein the noble metal particle is dispersed and supported on the outer and inner surfaces of the support. The process for producing an exhaust gas purifying catalyst comprises masking, in a solution, at least a part of the surface of a crystalline metal oxide support by a masking agent, introducing the support into a noble metal-containing solution containing a noble metal, and drying and firing the support and the noble metal-containing solution to support the noble metal on the support.

Abstract: A process for biomass catalytic cracking is disclosed herein. More specifically, the process is in presence of is a mixed metal oxide catalyst represented by the formula (X1O).(X2O)a.(X3YbO4) wherein X1, X2 and X3 are alkaline earth elements selected from the group of Mg, Ca, Be, Ba, and mixture thereof, and Y is a metal selected from the group of Al, Mn, Fe, Co, Ni, Cr, Ga, B, La, P and mixture thereof, wherein the catalyst is formed by calcining at least one compound comprising at least one alkaline earth element and a metal element.

Abstract: Disclosed is a visible light responsive photocatalyst that simultaneously realizes high crystallinity and refinement of primary particles. Also disclosed is a photocatalyst composed of secondary particles that have a high porosity and are aggregates of fine primary particles. Rhodium-doped strontium titanate that is a visible light responsive photocatalyst of the present invention has a primary particle diameter of not more than 70 nm and has a absorbance at a wavelength of 570 nm of not less than 0.6 and a absorbance at a wavelength of 1800 nm of not more than 0.7, each absorbance determining by measuring a diffuse reflection spectrum, the rhodium-doped strontium titanate having a high water-splitting activity as a photocatalyst.