Provided is an electrode catalyst in which the contents of chlorine (Cl) species and bromine (Br) species are reduced to a predetermined level or lower, capable of exhibiting sufficient catalyst performance. The electrode catalyst has a core-shell structure including a support, a core part formed on the support and a shell part formed to cover at least a part of the surface of the core part. A concentration of bromine (Br) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 400 ppm or less, and a concentration of chlorine (Cl) species of the electrode catalyst as measured by X-ray fluorescence (XRF) spectroscopy is 900 ppm or less.

A method for producing a catalyst-coated membrane includes: producing and/or providing at least one first ink with a first ink composition, comprising supported catalyst particles, a proton-conductive ionomer, and a dispersing agent, the content of the supported catalyst particles in the composition remaining below the content of the proton-conductive ionomer; unwinding a web-shaped proton-conductive membrane material which is provided on a roll; applying at least one layer of the first ink onto at least one section of the membrane material using a first application tool; and sputtering a catalyst powder consisting of or comprising catalyst particles onto a surface of the outermost ink layer facing away from the membrane material using a sputtering device.

Provided is a gas detection device that includes a gas sensor, a power supply circuit that applies voltage to the gas sensor, and a control circuit that determines whether a leak of gas is present. The power supply circuit includes a reset power source that generates a first voltage, and a detection power source that generates a detection voltage for measuring resistance of a metal-oxide layer of the gas sensor. When a value of a current flowing through the metal-oxide layer is a predetermined value ITH or greater, the reset power source applies the first voltage to the gas sensor to perform a reset of resetting the metal-oxide layer of the gas sensor to a high-resistance state, and the control circuit determines that a leak of gas is present, depending on a state in which the reset is performed after the reset is performed for the first time.

Provided is an electrochemical oxygen reduction catalyst comprising platinum-containing nanoparticles and at least one member selected from the group consisting of a specific polymer containing a melamine compound as a monomer and a specific melamine compound, the electrochemical oxygen reduction catalyst having not only high oxygen reduction activity (low overvoltage), but also high durability at 70 to 85° C., which are practical temperature conditions.

A nanowire catalyst for a fuel cell has a porous structure in which first and second pores having predetermined pore sizes are uniformly dispersed inside and on the surface thereof at a predetermined volume ratio. This enables the efficient exposure of active sites and efficient mass transfer, thereby improving fuel cell performance.

An anode catalyst layer of an electrochemical cell includes an anode catalyst material. The anode catalyst material is a Pt-based alloy. The Pt-based alloy is a binary Pt-M alloy, where M is Ge, Se, Ag, Sb, Os, or Tl. The Pt-based alloy is a ternary Pt-M.sup.I-M.sup.II alloy, where M.sup.I is Ru, Ge, or Mo, and M.sup.II is Ir, Os, Tl, Au, Bi, Se, or Pd.

A membrane electrode assembly (MEA) includes an ionically-conductive proton exchange membrane, an anode contacting a first side of the membrane and a cathode contacting a second side of the membrane and including third catalyst particles and a cathode GDL. The anode includes an anode gas diffusion layer (GDL), a first anode catalyst layer containing first catalyst particles, a hydrophobic polymer bonding agent, and a first ionomer bonding agent that lacks functional chains on a molecular backbone, and a second anode catalyst layer containing second catalyst particles and a second ionomer bonding agent that includes functional chains on a molecular backbone.

Disclosed are a method of manufacturing an anode dual catalyst for a fuel cell so as to prevent a reverse voltage phenomenon and a dual catalyst manufactured by the same. The method may include supporting effectively metal catalyst particles and oxide particles on a conductive support, and thus, a dual catalyst manufactured using the method may be suitably used for controlling a reverse voltage phenomenon that occurs at the anode.

Catalyst comprising a first layer having an outer layer with a layer comprising Pt directly thereon, wherein the first layer has an average thickness in a range from 0.04 to 30 nanometers, and wherein the layer. Catalysts described herein are useful, for example, in fuel cell membrane electrode assemblies.

A carbon monoxide (CO) tolerant membrane electrode assembly (MEA) includes an ionically-conductive proton exchange membrane, an anode contacting a first side of the membrane and including a hydrophobic bonding agent, an ionomer bonding agent, first catalyst particles, second catalyst particles, and an anode gas diffusion layer (GDL), a cathode contacting a second side of the membrane and including a cathode GDL. The first catalyst particles are configured to preferentially catalyze oxidation of CO, and the second catalyst particles are configured to preferentially catalyze generation of hydrogen ions.