Abstract: A catalyst deterioration recovery device in a fuel cell system that includes a fuel cell including a membrane electrode assembly configured to include an electrolyte membrane and anode and cathode catalysts between which the electrolyte membrane is sandwiched from both sides and anode and cathode separators respectively including an anode gas flow channel and a cathode gas flow channel, the membrane electrode assembly being sandwiched between the anode and cathode separators. The catalyst deterioration recovery device recovers performance decreased by adsorption of carbon monoxide to the anode catalyst. The catalyst deterioration recovery device includes a recovery control unit configured to supply at least a part of oxygen to be supplied to the cathode gas flow channel to the anode catalyst via the electrolyte membrane.

Abstract: A catalyst deterioration recovery device in a fuel cell system that includes a fuel cell including a membrane electrode assembly configured to include an electrolyte membrane and anode and cathode catalysts between which the electrolyte membrane is sandwiched from both sides and anode and cathode separators respectively including an anode gas flow channel and a cathode gas flow channel, the membrane electrode assembly being sandwiched between the anode and cathode separators. The catalyst deterioration recovery device recovers performance decreased by adsorption of carbon monoxide to the anode catalyst. The catalyst deterioration recovery device includes a recovery control unit configured to supply at least a part of oxygen to be supplied to the cathode gas flow channel to the anode catalyst via the electrolyte membrane.

Abstract: To provide a catalyst layer for a fuel cell, which exhibits excellent power generation performance even in the case of reducing the used amount of a catalyst. It is an electrode catalyst layer for a fuel cell comprising a catalyst, a porous carrier for supporting the above-mentioned catalyst, and a polymer electrolyte, in which a mode diameter of the pore distribution of the above-mentioned porous carrier is 4 to 20 nm, and the above-mentioned catalyst is supported in a pore with a pore diameter of 4 to 20 nm of the above-mentioned porous carrier.

Abstract: Provided is an electrode catalyst layer excellent in gas transportability by using an electrode catalyst layer for fuel cell comprising a catalyst containing a catalyst carrier and a catalytic metal carried on the catalyst carrier and an electrolyte, wherein the catalyst partially is coated with the electrolyte, and a specific surface area of the catalytic metal which gas can reach without passing through an electrolyte is 50% or more, with respect to the total specific surface area of the catalytic metal.

Abstract: Provided is an electrode catalyst layer excellent in gas transportability by using an electrode catalyst layer for fuel cell comprising a catalyst containing a catalyst carrier and a catalytic metal carried on the catalyst carrier and an electrolyte, wherein the catalyst partially is coated with the electrolyte, and a specific surface area of the catalytic metal which gas can reach without passing through an electrolyte is 50% or more, with respect to the total specific surface area of the catalytic metal.

Abstract: Provided is an electrocatalyst for solid polymer fuel cells capable of increasing the active surface area for reactions in a catalyst component, increasing the utilization efficiency of the catalyst, and reducing the amount of expensive precious metal catalyst used. Also provided are a membrane electrode assembly that uses this electrocatalyst and a solid polymer fuel cell. An electrocatalyst for a solid polymer fuel cell is provided with a catalyst and solid proton conducting material. A liquid conductive material retention part that retains a liquid proton conducting material that connects the catalyst and solid proton conducting material is provided between the same. The surface area of the catalyst exposed within the liquid conductive material retention part is larger than the surface area of the catalyst in contact with the solid proton conducting material.

Abstract: This electrode catalyst layer for fuel cells is provided with: an electrode catalyst that comprises a conductive carrier and platinum-containing metal particles supported on the surface of the conductive carrier; and an ionomer that covers the electrode catalyst. This electrode catalyst layer for fuel cells is characterized in that the average thickness of the ionomer is 2.4 nm or less. This electrode catalyst layer for fuel cells is capable of having a good balance between proton transport properties and transport properties for a gas such as an oxidant gas or a fuel gas even in cases where the amount of supported platinum is decreased. In addition, an electrode for fuel cells, a membrane electrode assembly for fuel cells, and a fuel cell, each having good current-voltage characteristics, can be obtained using the above-described electrode catalyst layer for fuel cells.

Abstract: A performance recovery operation for a fuel cell system effectively restores a fuel electrode such that, upon starting or stopping of operation of the fuel cell, both fuel and oxidizing electrodes are disposed in a hydrogen atmosphere and then the fuel electrode is maintained at a higher potential level than in a normal operation.

Abstract: [Object] To provide a gas diffusion electrode capable of a high current density operation of a fuel cell. [Solving means] A gas diffusion electrode including a hydrophilic porous layer having an electrically conductive material and an ion conductive material; and a catalyst layer adjacent to the hydrophilic porous layer, wherein a water transport resistance of the hydrophilic porous layer is smaller than a water transport resistance of the catalyst layer.

Abstract: To provide a catalyst layer for a fuel cell, which exhibits excellent power generation performance even in the case of reducing the used amount of a catalyst. It is an electrode catalyst layer for a fuel cell comprising a catalyst, a porous carrier for supporting the above-mentioned catalyst, and a polymer electrolyte, in which a mode diameter of the pore distribution of the above-mentioned porous carrier is 4 to 20 nm, and the above-mentioned catalyst is supported in a pore with a pore diameter of 4 to 20 nm of the above-mentioned porous carrier.

Abstract: This electrode catalyst layer for fuel cells is provided with: an electrode catalyst that comprises a conductive carrier and platinum-containing metal particles supported on the surface of the conductive carrier; and an ionomer that covers the electrode catalyst. This electrode catalyst layer for fuel cells is characterized in that the average thickness of the ionomer is 2.4 nm or less. This electrode catalyst layer for fuel cells is capable of having a good balance between proton transport properties and transport properties for a gas such as an oxidant gas or a fuel gas even in cases where the amount of supported platinum is decreased. In addition, an electrode for fuel cells, a membrane electrode assembly for fuel cells, and a fuel cell, each having good current-voltage characteristics, can be obtained using the above-described electrode catalyst layer for fuel cells.

Abstract: Provided is an electrocatalyst for solid polymer fuel cells capable of increasing the active surface area for reactions in a catalyst component, increasing the utilization efficiency of the catalyst, and reducing the amount of expensive precious metal catalyst used. Also provided are a membrane electrode assembly that uses this electrocatalyst and a solid polymer fuel cell. An electrocatalyst for a solid polymer fuel cell is provided with a catalyst and solid proton conducting material. A liquid conductive material retention part that retains a liquid proton conducting material that connects the catalyst and solid proton conducting material is provided between the same. The surface area of the catalyst exposed within the liquid conductive material retention part is larger than the surface area of the catalyst in contact with the solid proton conducting material.

Abstract: [Summary] [Object] To provide a hydrophilic porous layer for a fuel cell that improves a sub-zero temperature starting ability of the fuel cell. [Solving means] A hydrophilic porous layer comprising electrically conductive material—hydrophilic material aggregates each including hydrophilic materials and electrically conductive materials that intimately contact to one another, the hydrophilic materials being mutually connected to one another to form in the hydrophilic materials a continuous transport path for water, the electrically conductive material—hydrophilic material aggregates forming therebetween a transport path for water vapor, which is characterized in that when it is above ?40° C., a water transport resistance Rwater of the water transport path is larger than a water vapor transport resistance Rgas of the water vapor transport path.

Abstract: [Object] To provide a gas diffusion electrode capable of a high current density operation of a fuel cell. [Solving means] A gas diffusion electrode including a hydrophilic porous layer having an electrically conductive material and an ion conductive material; and a catalyst layer adjacent to the hydrophilic porous layer, wherein a water transport resistance of the hydrophilic porous layer is smaller than a water transport resistance of the catalyst layer.

Abstract: A performance recovery operation for a fuel cell system effectively restores a fuel electrode such that, upon starting or stopping of operation of the fuel cell, both fuel and oxidizing electrodes are disposed in a hydrogen atmosphere and then the fuel electrode is maintained at a higher potential level than in a normal operation.