The present invention relates to an oxygen reduction catalyst, an electrode, a membrane electrode assembly, and a fuel cell, and the oxygen reduction catalyst is an oxygen reduction catalyst containing substituted CoS.sub.2, in which the substituted CoS.sub.2 has a cubic crystal structure, the oxygen reduction catalyst contains the substituted CoS.sub.2 within 0.83 nm from the surface thereof, and the substituted CoS.sub.2 has at least one substitutional atom selected from the group consisting of Cr, Mo, Mn, Tc, Re, Rh, Cu, and Ag in some of Co atom sites.

A bifunctional oxygen electrocatalyst, a preparation method and use thereof are disclosed. The bifunctional oxygen electrocatalyst is represented by A1-x-yBxCyO2, wherein element A is one selected from the group consisting of Pt, Ir, Ru, and Pd, and each of element B and element C is selected from the group consisting of Mo, Mn, Fe, Co, Ni, Cu and Zn; the bifunctional oxygen electrocatalyst is a three-dimensional porous foam sheet catalyst; optionally, the element B is the same as the element.

The present invention relates to a catalyst composition, comprising tin oxide particles which are at least partially coated by a noble metal oxide layer, wherein the composition contains iridium and ruthenium in a total amount of from 10 wt % to 38 wt %, and all iridium and ruthenium is oxidized, has a BET surface area of from 5 to 95 m.sup.2/g, and has an electrical conductivity at 25 C. of at least 7 S/cm.

The present invention provides a highly conductive electrode material having high oxygen reduction activity. The present invention also provides an electrode material composition and a fuel cell each containing the electrode material. The present invention relates to an electrode material having a structure containing a noble metal and/or an oxide thereof supported on titanium oxynitride or a composite compound of titanium oxynitride and an oxide of titanium. The titanium oxynitride or the composite compound of titanium oxynitride and an oxide of titanium is in the form of powder. The electrode material has pore diameter distribution satisfying the following features (I) and (II): (I) a ratio (b/a) of a peak area b in a pore diameter range of 50 to 180 nm to a peak area a in a pore diameter range of 0 to 180 nm, calculated from log differential pore volume distribution, being 0.9 or more, and (II) a cumulative pore volume in a pore diameter range of 50 to 180 nm being 0.1 cm.sup.3/g or greater.

The present subject matter relates generally to the derivatization of highly-aligned carbon nanotube sheet substrates with one or more transition metal centers and to uses of the resulting metal-derivatized CNT sheet substrates.

Provided is a catalyst having excellent gas transportability. Disclosed is a catalyst comprising a catalyst support and a catalyst metal supported on the catalyst support, wherein the catalyst includes pores having a radius of less than 1 nm and pores having a radius of 1 nm or more, wherein a pore volume of the pores having a radius of less than 1 nm is 0.3 cc/g support or more or a mode radius of a pore distribution of the pores having a radius of less than 1 nm is 0.3 nm or more and less than 1 nm, and wherein the catalyst metal is supported inside the pores having a radius of 1 nm or more.

The present invention discloses a palladium oxide catalyst for a direct formic acid fuel cell and a preparation method thereof The preparation method is as follows: dissolving a palladium chloride to prepare an aqueous solution, adding a sodium citrate or a potassium citrate, adjusting the solution to a pH value ranging from 9 to 13; then, placing the above solution in a microwave reactor for microwave reaction for 3 minutes to 30 minutes, and refluxing and magnetically stirring simultaneously during the reaction to obtain a palladium oxide collid solution; after the palladium oxide colloid is cooled, adding a commercial carbon powder or a carbon nanotube to collect the palladium oxide; and performing suction filtration finally, washing a filter cake, drying the filter cake under vacuum, and grounding the filter cake to obtain a carbon-supported palladium oxide catalyst.

A synthesis method of a metal catalyst having carbon shell, includes: a) forming a metal-ligand complex without further chemical additives by mixing a ligand with a metal precursor; b) separating the metal-ligand complex and collecting the separated metal-ligand complex; c) supporting the collected metal-ligand complex to a support by mixing the collected metal-ligand complex with the support in a solvent; and d) treating a composite consisting of the metal-ligand complex and the support by heating.

A catalyst particle is composed of an inner particle and an outermost layer that includes platinum and covers the inner particle. The inner particle includes on at least a surface thereof a first oxide having an oxygen defect.

An oxygen evolution catalyst includes a core and a shell covering the surface of the core. The core includes ruthenium oxide or metal ruthenium in at least a surface portion. The shell includes titania or a composite oxide of titanium and ruthenium. Such an oxygen evolution catalyst is obtained by (a) dispersing core particles each including ruthenium oxide or metal ruthenium in at least a surface portion in a solvent to obtain a dispersion, (b) adding a Ti source to the dispersion to produce precursor particles in which the surface of each core particle is covered with a titania precursor, and (c) collecting the precursor particles from the dispersion and heat-treating the precursor particles after drying.