A catalyst includes a mesoporous material and catalytic metal particles supported at least within the mesoporous material and containing platinum and a metal different from platinum. The mesoporous material has mesopores with a mode radius of 1 to 25 nm and a pore volume of 1.0 to 3.0 cm.sup.3/g before supporting of the catalytic metal particles, and has an average particle size of greater than or equal to 200 nm. A molar ratio of the metal different from platinum and contained in the catalytic metal particles relative to all metals contained in the catalytic metal particles is greater than or equal to 0.25, and among the catalytic metal particles, a volume ratio of catalytic metal particles having a particle size of greater than or equal to 20 nm is less than or equal to 10%.

A support powder can improve cell performance under high humidity environment. A support and metal catalyst, including: a support powder; and metal fine particles supported on the support powder; wherein: the support powder is an aggregate of support fine particles; the support fine particles are fine particles of oxide compound and has a chained portion structured by a plurality of crystallites being fusion bonded to form a chain; the crystallites have a size of 10 to 30 nm; the support powder has a void; the void includes a secondary pore having a pore diameter of more than 25 nm and 80 nm or less determined by BJH method; and a volume of the secondary pore per unit volume of the support fine particles structuring the support powder is 0.313 cm.sup.3/cm.sup.3 or more, is provided.

Disclosed is, inter alia, a method of producing a platinum alloy catalyst using a carbon protective layer. The method includes depositing a transition metal precursor on a Pt/C catalyst including a platinum component and a carbon carrier, placing carbon at the bottom of a reactor separately from the transition metal precursor-deposited Pt/C catalyst by a separation membrane; performing heat treatment on the inside of the; forming a Pt-M/C catalyst coated with a carbon protective layer by passing a gas product generated through thermal decomposition of the placed carbon through the separation membrane, and removing the carbon protective layer from the Pt-M/C catalyst by performing acid treatment on the carbon protective layer coated on the Pt-AMC catalyst.

One variation of the method includes: receiving a section of a substrate tape including a substrate within a coating zone; depositing a constellation of separator material droplets over the first substrate, each droplet in the constellation of separator material droplets including a first solvent, a first polymer, and a second polymer; heating the substrate and the proportion of the separator material to a first temperature; dissolving the second polymer out of the constellation of separator material droplets to render an open-celled network of pores by washing the constellation of separator material droplets and the substrate with a second solvent; and irradiating the constellation of separator material droplets to crosslink the first polymer and form a discrete separator layer with the open-celled network of pores sized to transport ions through the discrete separator layer.

A hydrophilic porous carbon electrode which has excellent hydrophilicity, which has high reaction activity when used for a battery, and with which excellent battery characteristics is able to be obtained is provided. A hydrophilic porous carbon electrode is a sheet-form hydrophilic porous carbon electrode in which a carbon fiber is bonded using a resin carbide and has a contact angles θ.sub.A of water on both surfaces in a thickness direction being 0 to 15° and a contact angle θ.sub.B of water in a middle portion in the thickness direction being 0 to 15°. The hydrophilic porous carbon electrode is obtained by forming the carbon fiber and a binder fiber into a sheet, impregnating the sheet into a thermosetting resin, subjecting it to heat press processing, and then subjecting it to carbonization at 400 to 3000° C. in an inert atmosphere. The hydrophilic porous carbon electrode is transported and is subjected to a heat treatment while an oxidizing gas flows at 400 to 800° C. in a direction perpendicular to a direction in which the hydrophilic porous carbon electrode is transported to be subjected to hydrophilization.

The metal porous body having a framework of a three-dimensional network structure is disclosed. The framework is formed of a metal film, the framework has an interior that is hollow, and the metal film contains titanium metal or titanium alloy as a main component.

A support powder can improve cell performance under high humidity environment. A support and metal catalyst, including: a support powder; and metal fine particles supported on the support powder; wherein: the support powder is an aggregate of support fine particles; the support fine particles are fine particles of oxide compound and has a chained portion structured by a plurality of crystallites being fusion bonded to form a chain; the crystallites have a size of 10 to 30 nm; the support powder has a void; the void includes a secondary pore having a pore diameter of more than 25 nm and 80 nm or less determined by BJH method; and a volume of the secondary pore per unit volume of the support fine particles structuring the support powder is 0.313 cm.sup.3/cm.sup.3 or more, is provided.

In order to provide a gas diffusion electrode medium having high thermal conductivity despite having low density and excellent both in handleability and cell performance, provided is a gas diffusion electrode medium including carbon fiber felt including carbon fibers having an average fiber diameter of 5 to 20 μm, wherein at least a part of the carbon fibers that constitute the carbon fiber felt have a flat part in which, in a plane view of a surface of the carbon fiber felt, a maximum value of a fiber diameter is observed to be 10 to 50% larger than the average fiber diameter, and a frequency of the flat parts at the surface of the carbon fiber felt is 50 to 200/mm.sup.2.

The present disclosure relates to a cathode for a lithium air battery and a method of manufacturing the same, and more particularly to a method of manufacturing a cathode for a lithium air battery, in which a hollow structure including a carbon material having a nitrogen functional group is synthesized through electrospinning of a thermally decomposable polymer, coating with a nitrogen-containing polymer and heat treatment, and is utilized without a binder as a cathode carbon material for a lithium air battery, thereby increasing the performance and lifespan of a lithium air battery.

A cathode configured to use oxygen as a cathode active material, the cathode including: a porous film, wherein the porous film includes a metal oxide, and wherein a surface of the porous film has root mean square (RMS) roughness (Rq) of about 0.01 micrometer to about 1 micrometer, and a porosity of the porous film is about 50 volume percent to about 99 volume percent, based on a total volume of the porous film.