The invention relates to electrochemical current sources, more particularly to metal-air current sources, and even more particularly to lithium-air current sources and their electrodes. A cathode comprises a base made of a porous electrically conducting material that is permeable to molecular oxygen, the working surface of which has a copolymer applied thereto, which is produced by the copolymerization of a monomeric transition metal coordination complex having a Schiff base and a thiophene group monomer. The monomeric transition metal coordination complex having a Schiff base can be, for example, a compound of the [M(R,R-Salen)], [M(R,R-Saltmen)] or [M(R,R-Salphen)] type, and the thiophene group monomer can be a compound selected from a thiophene group consisting of 3-alkylthiophenes, 3,4-dialkylthiophenes, 3,4-ethylenedioxythiophene or combinations thereof. A current source comprises the described cathode and an anode made from an active metal, in particular lithium, wherein the cathode and the anode are separated by an electrolyte containing ions of the metal from which the anode is made. It has been established that in this system, the copolymer exhibits the properties of an effective catalyst. The technical result is an increase in the specific energy, specific power and number of charge and discharge cycles of a metal-air current source.

An inorganic structure body has a free-standing structure including a fibrous member and/or a shell. The fibrous member and/or the shell include a metal and/or an inorganic material and have a three-dimensionally continuous configuration. The free-standing structure may have a structure that is based on a nonwoven fabric or a porous membrane used as a substrate.

A specific method for preparing platinum particles grafted with proton-conducting polymers and use of these particles as catalysts for oxygen reduction.

The present invention aims to provide a catalyst that makes it possible to reduce an amount of solid electrolyte mixed and improve initial performance of a fuel cell, and also a method for producing the catalyst. The present invention relates to a catalyst for a solid polymer fuel cell, which has sulfo groups (SO.sub.3H) on catalyst particles. In TEM-EDX analysis, a ratio (I.sub.S/I.sub.Pt) of a sulfur peak intensity (I.sub.S) to a platinum peak intensity (I.sub.Pt) on the catalyst particles is within a range of 0.0044 or more and 0.0090 or less. The catalyst makes it possible to reduce the amount of solid electrolyte added and also a fuel cell with excellent initial performance, and thus contributes to a practical use of a fuel cell.

Provided is an electrode catalyst for fuel cells. The electrode catalyst for fuel cells includes a core including an alloy of platinum, copper, and metal oxide and a shell including platinum or a platinum alloy material.

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.

An electrocatalyst is provided. The electrocatalyst includes Pd-containing metal nitride, wherein the metal is Co, Fe, Y, Lu, Sc, Ti, V, Cu, Ni, or a combination thereof. The molar ratio between the metal and Pd is greater than 0 and less than or equal to 0.8. A fuel cell utilizing the above electrocatalyst is further provided.

A cathode can include: an electrode substrate; a porphyrin precursor attached to the substrate; and an enzyme coupled to the electrode substrate to be associated with the porphyrin precursor, the enzyme reduces oxygen. The cathode can include a conductive material associated with the porphyrin precursor and/or the enzyme. The cathode can include 1-pyrenebutanoic acid, succinimidyl ester (PBSE) associated with the porphyrin precursor and/or the enzyme and/or the conductive material. The cathode can include 2,5-dimethyl-1-phenyl-1H-pyrrole-3-carbaldehyde (DMY-Carb) associated with the 1-pyrenebutanoic acid, succinimidyl ester (PBSE) and/or the porphyrin precursor and/or the enzyme and/or the conductive material. The porphyrin precursor is attached to the substrate through covalent coupling. In some aspects, substrate is linked to the porphyrin precursor, the porphyrin precursor is linked to the conductive material, the conductive material is linked to the PBSE, the PBSE is linked to the DMY-carb, and the DMY-carb is linked to the enzyme.

An anode can include: an electrode substrate; a first region of the substrate having a catalyst composition located thereon, wherein the catalyst composition includes an inorganic or metallic catalyst; and a second region of the substrate having an enzyme composition located thereon, wherein the combination of the catalyst composition and enzyme composition converts a fuel reagent to carbon dioxide at neutral pH. The first region and second region can be separate regions. The catalyst of the catalyst composition can include gold nanoparticles. The catalyst can include an inorganic or metallic catalyst selected from vanadium oxide, titanium (III) chloride, Pd(OAc).sub.2, MnO, zeolite, alumina, graphitic carbon, palladium, platinum, gold, ruthenium, rhodium, iridium, or combinations thereof. The catalyst can be nanoparticle, nanorod, nanodot, or combination thereof. The catalyst can have sizes that range from about 10 to 20 nm.

[Object] Provided is a catalyst having excellent gas transportability. [Solving Means] 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.