An electrode catalyst layer for fuel cells capable of effectively preventing reduction of cell voltage in a high current density region. The electrode catalyst layer contains a catalyst-on-support composed of a support made of a conductive inorganic oxide having a catalyst supported thereon and a hydrophilic material. The hydrophilic material is an agglomerate including hydrophilic conductive particles. The content of the hydrophilic material in the catalyst layer is 2 mass % or higher and lower than 20 mass % relative to the sum of the support and the hydrophilic material. The ratio of the particle size d1 of the hydrophilic particles to the particle size D of the catalyst-on-support is 0.5 to 3.0. The ratio of the particle size d2 of the hydrophilic material to the thickness T of the catalyst layer is 0.1 to 1.2.

Aspects of this disclosure pertain to catalyst compositions that include electrically conductive support particles; and metal catalyst particles attached to the electrically conductive support particles. The catalyst compositions may be used in cathodes of carbon oxide reduction electrolyzers.

A method of making a catalyst layer of a membrane electrode assembly (MEA) for a polymer electrolyte membrane fuel cell includes the step of preparing a porous buckypaper layer comprising at least one selected from the group consisting of carbon nanofibers and carbon nanotubes. Platinum group metal nanoparticles are deposited in a liquid solution on an outer surface of the buckypaper to create a platinum group metal nanoparticle buckypaper. A proton conducting electrolyte is deposited on the platinum group metal nanoparticles by electrophoretic deposition to create a proton-conducting layer on the an outer surface of the platinum nanoparticles. An additional proton-conducting layer is deposited by contacting the platinum group metal nanoparticle buckypaper with a liquid proton-conducting composition in a solvent. The platinum group metal nanoparticle buckypaper is dried to remove the solvent. A membrane electrode assembly for a polymer electrolyte membrane fuel cell is also disclosed.

To make adhesiveness of a catalyst layer and a solid polymer electrolyte membrane be compatible with electrolysis performance without the need for weighting components even when an electrolyte is included in the catalyst layer, the rate of mass of the electrolyte/the catalyst of the catalyst layer including a catalyst and the electrolyte is more than 0.05 and less than 0.2.

A method for depositing a ruthenium-containing film on a substrate by a cyclical deposition process is disclosed. The method may include: contacting the substrate with a first vapor phase reactant comprising a metalorganic precursor, the metalorganic precursor comprising a metal selected from the group consisting of platinum, aluminum, titanium, bismuth, zinc, and combination thereof. The method may also include; contacting the substrate with a second vapor phase reactant comprising ruthenium tetroxide, wherein the ruthenium-containing film comprises at least one of a ruthenium-platinum alloy, or a ternary ruthenium oxide. Device structures including a ruthenium-containing film deposited by the methods of the disclosure are also disclosed.

Methods of forming a metal-alloy graphene nanocomposites are provided. The methods include providing a graphene substrate and forming a conducting polymer layer on a first major surface of the graphene substrate. The methods also include pyrolyzing the conducting polymer layer to form a nitrogen-doped graphene substrate and dispersing a plurality of metal-alloy nanoparticles on a first surface of the nitrogen-doped graphene substrate to form the nanocomposite.

Disclosed are a catalyst complex which may suppress cell voltage reversal in a fuel cell and a method for manufacturing the same. The catalyst complex includes a support, a first catalytic active material supported on the support and comprising a platinum component including one or more selected from the group consisting of platinum and a platinum alloy, and a second catalytic active material supported on the support and comprising one or more selected from a noble metal other than platinum and an oxide thereof, and the support includes functional groups including oxygen.

Compositions comprised of a tin film, coated by a shell of less than 50 nm thick made of palladium and tin in a molar ratio ranging from 1:4 to 3:1, respectively, are disclosed. Uses of the compositions as an electro-catalyst e.g., in a fuel cell, and particularly for the oxidation of various materials are also disclosed.

Disclosed is a catalyst layer for a fuel cell that has good gas diffusion properties in the entire catalyst layer and in which coarsening of catalyst particles can be suppressed. The catalyst layer for a fuel cell includes fibrous conductive members and catalyst particles. The fibrous conductive members are inclined relative to the surface direction of the catalyst layer, and the length L of the fibrous conductive members and the thickness T of the catalyst layer satisfy the relational expression: L/T≤3. Each of the catalyst particles includes a core portion and a shell portion that covers the core portion, and contains a component different from that of the core portion.

A core-shell composite material may include a core consisting of Nb-doped TiO.sub.2 of formula TiNbO.sub.x; and a shell consisting of a homogeneous layer of Pt or Pt alloy of 1 to 50 ML in thickness. The core-shell composite material may in particular find application in fuel cells.