Disclosed is a direct synthesis method of nanostructured catalyst particles on surfaces of various supports. In the disclosed synthesis method of a catalyst structure having a plurality of nanostructured catalyst particles dispersed in a support by a one-step process using a high-temperature high-pressure closed reactor, the one-step process includes supplying the support and a catalyst source into the high-temperature high-pressure closed reactor; supplying an atmosphere forming gas of the reactor into the reactor; perfectly sealing the high-temperature high-pressure closed reactor and heating the reactor to produce the catalyst structure in the reactor under self-generated pressure and synthesis temperature conditions, the catalyst structure including the plurality of nanostructured catalyst particles dispersed in the support; removing internal gases of the reactor to allow the reactor to be in a high-temperature, atmospheric pressure state and supplying an inert gas into the reactor to remove unreacted materials and byproducts remaining in the reactor; and cooling the reactor to room temperature while supplying the inert gas to synthesize the catalyst structure.

The present invention relates to a method for producing a platinum-based alloy powder, the method comprising a heat treatment of a mixed powder containing a platinum-based powder composed of at least one selected from the group consisting of platinum and platinum compound, a platinum group metal-based powder composed of at least one selected from the group consisting of iridium, rhodium, palladium, and compound containing at least one of them, and an alkaline-earth metal compound, wherein specific surface area of the platinum group metal-based powder is 30 m.sup.2/g or more and D90 of the mixed powder is 1.0 μm or less. According to the method for producing a platinum-based alloy powder of the invention, it is possible to produce a platinum-based alloy powder that has a desired particle diameter, also has a sharp particle size distribution, and has high purity and crystallinity.

The present invention relates to a catalytically active material for the electrochemical oxidation of water, wherein the catalytically active material comprises an amorphous Ir-oxohydroxide, wherein the catalytically active material has a specific surface area (S.sub.BET) of ≥50 m.sup.2.g.sup.−1; an electrode coated with the catalytically active material; a proton exchange membrane (PEM) based electrolyzer comprising the electrode; the use of the catalytically active material, the electrode or the electrolyzer the electrochemical oxidation of water; and a process for preparing the catalytically active material comprising the microwave-assisted thermal treatment of a basic solution of an Ir(III) or Ir(IV) complex.

An embodiment provides a catalyst for water electrolysis which includes an iridium mixed phase formed by physical mixing of two or more selected from metal iridium (Ir), iridium(III) oxide (Ir.sub.2O.sub.3), or iridium(IV) oxide (IrO.sub.2) and has a structure in which nanosheets composed of the iridium mixed phase are stacked. The catalyst for water electrolysis may exhibit high activity and stability for the oxygen evolution reaction in water electrolysis.

Methods of converting ethane to ethylene at relatively low temperatures are described. Ir02-based catalysts are used in the conversion. Methods of converting a base gas to a first gas by exposing the base gas to an IrO2-based catalyst and forming the first gas are described. The base gas can be an alkane. The first gas can include an alkene, an alkyne, an alcohol, an aldehyde, or combinations thereof.

Provided is a method for manufacturing a single-atom catalyst supported on a carbon support, including treating a mixture of a precursor of a carbon support and a precursor of a hetero element other than carbon through a dry vapor phase process, thereby supporting, on a carbon support, a single-atom catalyst containing a hetero element other than carbon.

A problem of the present invention is to provide a solid polymer membrane electrode capable of obtaining electrolyzed hydrogen water in which an increase of the pH is suppressed and which has a sufficient dissolved-hydrogen amount. The present invention is concerned with a solid polymer membrane electrode for generating electrolyzed water, wherein the solid polymer membrane electrode includes a solid polymer membrane and catalyst layers containing a platinum group metal and provided on the back and front of the solid polymer membrane; and the solid polymer membrane is a hydrocarbon-based cation exchange membrane and has an ion exchange capacity per unit area of 0.002 mmol/cm.sup.2 or more and 0.030 mmol/cm.sup.2 or less.

A method for producing plasmonic nanomaterials that are catalytically or photocatalytically active by fabricating plasmonic nanostructures on substrates using electrodeposition into a nano-template structure and forming a plurality of nanorods in an array, wherein the nanorods are made from materials chosen from the group consisting of materials that are plasmonic and/or catalytic, and materials that are catalytically activated by depositing pure elemental metals, alloys, or alternating layers of different metals or alloys, and producing catalytic plasmonic nanomaterials. Catalytic plasmonic nanomaterials made from the above method. An optical reactor device that utilizes catalytic nanomaterials for photocatalytic synthesis of methanol or ammonia. A method of photocatalytic synthesis of methanol and ammonia by using catalytic plasmonic nanomaterial to convert CO.sub.2 and H.sub.2 to methanol and N.sub.2 and H.sub.2 to ammonia using optical power. A hybrid plasma-plasmonic reactor for the utilization of CO.sub.2 and CH.sub.4 to produce methanol, ethylene, and acetic acid.

A method for producing a catalyst for an electrochemical reaction that can be sized into fine particles while having a high specific surface area by using a carbon-based spacer in the catalyst synthesis process includes preparing a mixture by mixing a carbon-based spacer and a catalyst precursor and heat-treating the mixture.

A catalyst comprising a carrier and a metals component impregnated in the carrier, the carrier comprising alumina; and the metals component comprising a first metals fraction and a second metals fraction, the first metals fraction comprising at least one metal selected from chromium, molybdenum, or tungsten, and the second metals fraction comprising at least two metals selected from cobalt, rhodium, iridium, nickel, palladium, or platinum, wherein the catalyst has a first pore volume of 0.28 to 0.45 mL/g for pores having a pore diameter of 12 nm to less than 16 nm, and a second pore volume of 0.15 to 0.28 mL/g for pores of 2.0 nm to less than 12.0 nm.