A porous body includes a framework having a three-dimensional network structure, the framework having a body including crystal grains including nickel and cobalt as constituent elements, the cobalt having a proportion in mass of 0.2 or more and 0.8 or less with respect to a total mass of the nickel and the cobalt, the crystal grains having a shorter grain diameter of 2 μm or more, as determined in a first observed image obtained by observing the body of the framework in cross section at a magnification of 200 times.

A fuel cell membrane electrode assembly and a polymer electrolyte fuel cell, which improve drainage in a high current range where a large amount of water is produced, without hindering water retention under low humidification conditions, and exhibit high power generation performance and durability even under high humidification conditions. A fuel cell membrane electrode assembly according to a first embodiment of the present invention includes a polyelectrolyte film, and two electrocatalyst layers sandwiching the polyelectrolyte film. At least one of the two electrocatalyst layers includes catalyst support particles with a hydrophobic coating, a polyelectrolyte, and a fibrous material having an average fiber diameter that is 10 nm or more and 300 nm or less. The fibrous material has a mass that is 0.2 times or more and 1.0 times or less the mass of the carrier in the catalyst support particles.

An electrode for a reaction in a chemical cell includes a substrate having a surface, an array of nanostructures supported by the substrate and extending outward from the surface of the substrate, each nanostructure of the array of nanostructures having a semiconductor composition, and a catalyst arrangement disposed along each nanostructure of the array of nanostructures, the catalyst arrangement comprising a metal-based catalyst for the reaction in the chemical cell. The semiconductor composition of each nanostructure of the array of nanostructures establishes sites at which the metal-based catalyst is anchored to the nanostructure. The array of nanostructures and the catalyst arrangement are configured such that the metal-based catalyst is distributed along sidewalls of each nanostructure of the array of nanostructures at an atomic scale.

A membrane electrode assembly and a polymer electrolyte fuel cell that are capable of improving water release in a high current region, where a large amount of water is generated, without impairing water retention under low humidity conditions, and also capable of exhibiting high power generation performance and durability under high humidity conditions, and also reducing the production cost of the electrode catalyst layer. A membrane electrode assembly of the present embodiment includes a polymer electrolyte membrane, and a pair of electrode catalyst layers sandwiching the polymer electrolyte membrane. At least one of the pair of electrode catalyst layers contains catalyst-supporting particles having a hydrophobic coating, hydrophobic polymer fibers, and a polymer electrolyte.

A battery includes: an electrode group including an air electrode and a negative electrode that are stacked with a separator interposed therebetween; and a container housing the electrode group together with an alkaline electrolyte liquid. The air electrode includes a catalyst for an air electrode. This catalyst for an air electrode is a catalyst for an air electrode including an oxide containing at least bismuth (Bi), ruthenium (Ru), sodium (Na), and oxygen, and Na/(Ru+Bi+Na) representing an atomic ratio of the sodium to a sum of the bismuth, the ruthenium, and the sodium is 0.126 or more and 0.145 or less.

A catalyst support material for an electrochemical system. The catalyst support material includes a metal material of SnWO.sub.4 reactive with H.sub.3O.sup.+, HF and/or SO.sub.3.sup.− to form reaction products in which the metal material of SnWO.sub.4 accounts for a stable molar percentage of the reaction products.

Nanostructured materials, and methods and apparatus for their production are provided. Nanostructured materials comprise nanofibers having nanoparticles deposited along the outer surface thereof. The size of the nanofibers and nanoparticles, and the spacing of such nanoparticles along the nanofibers may be controlled over a wide range. Nanostructured materials may comprise a plurality of such nanofibers interwoven together to form fiber cloth-like materials. Many materials may be used to form the nanofibers including polymer nanofiber materials (e.g., polyvinyl alcohol (PVA) polyvinylpyrrolidone (PVP), etc.) along with compatible nanoparticle materials (e.g., salts or other crystallizable materials).

The invention relates to a method for preparing a catalyst composition, wherein in an aqueous medium containing an iridium compound, at a pH 9, an iridium-containing solid is deposited on a support material, and the support material loaded with the iridium-containing solid is separated from the aqueous medium and dried, wherein, in the method, the support material loaded with the iridium-containing solid is not subjected to a thermal treatment at a temperature of more than 250° C. for a period of time of longer than 1 hour.

The present invention refers to new membrane-electrode assembly (MBA), methods of producing the same as well as fuel cell comprising said MBA.

A catalyst support material for a proton exchange membrane fuel cell (PEMFC). The catalyst support material includes a metal material of an at least partially oxidized form of TiNb.sub.3O.sub.6 reactive with H.sub.3O.sup.+, HF and/or SO.sub.3.sup.− to form reaction products in which the metal material of the at least partially oxidized form of TiNb.sub.3O.sub.6 accounts for a stable molar percentage of the reaction products.