The present invention is a catalyst for a solid polymer fuel cell including: catalyst particles of platinum, cobalt and manganese; and a carbon powder carrier supporting the catalyst particles, wherein the component ratio (molar ratio) of the platinum, cobalt and manganese of the catalyst particles is of Pt:Co:Mn=1:0.06 to 0.39:0.04 to 0.33, and wherein in an X-ray diffraction analysis of the catalyst particles, the peak intensity ratio of a CoMn alloy appearing around 2=27 is 0.15 or less on the basis of a main peak appearing around 2=40. It is particularly preferred that the catalyst have a peak ratio of a peak of a CoPt.sub.3 alloy and an MnPt.sub.3 alloy appearing around 2=32 of 0.14 or more on the basis of a main peak.

A catalyst of an embodiment includes a porous structure including aggregates of particles containing Ru and metal atoms M different from Ru. The particles are a metal oxide. A metal atom ratio of the metal atom M in a surface region of the porous structure is higher than that of the metal atom M in the porous structure as a whole.

The present invention comprises a plurality of fuel cells connected to each other in series, and a reformer configured to reform raw fuel, wherein reformed fuel by the reformer is supplied to a first stage of the plurality of fuel cells, and the fuel cell on the first stage is provided with a methane reaction suppressing function which suppresses reaction of methane included in the reformed fuel to a larger extent than at least one fuel cell on a second and later stages. Suppressing temperature drop due to endothermic reaction in the fuel cell on the first stage can improve the efficiency of electric power generation of the fuel cell system having the plurality of fuel cells arranged in series.

The invention relates to a water electrolysis device including a membrane-electrode assembly that includes a proton-exchange membrane and an anode active layer that includes an electrocatalytic material. The water electrolysis device further includes a water inlet collector and an oxygen outlet collector, a straight line connecting the water inlet collector to the oxygen outlet collector extending along a general flow direction. The water electrolysis device further includes an anode facing the anode active layer. In a section along a normal to the straight line, the anode has points that each have a combined distance with the water inlet collector and with the oxygen outlet collector, the combined distance for a first point at the periphery of the anode is at least 10% greater than the combined distance of a second point positioned on the straight line.

A microporous layer sheet for a fuel cell according to the present invention includes at least two microporous layers, which are stacked on a gas diffusion layer substrate, and contain a carbon material and a binder. Then, the microporous layer sheet for a fuel cell is characterized in that a content of the binder in the microporous layer as a first layer located on the gas diffusion layer substrate side is smaller than contents of the binder in the microporous layers other than the first layer. The microporous layer sheet for a fuel cell, which is as described above, can ensure gas permeability and drainage performance without lowering strength. Hence, the microporous layer sheet for a fuel cell, which is as described above, can contribute to performance enhancement of a polymer electrolyte fuel cell by application thereof to a gas diffusion layer.

The present invention relates to a catalyst for a solid polymer fuel cell, including platinum, cobalt, and zirconium supported as a catalytic metal on a carbon powder carrier, in which the supporting ratio of platinum, cobalt, and zirconium on the carbon powder carrier is Pt:Co:Zr=3:0.5 to 1.5:0.1 to 3.0 by molar ratio. In the present invention, it is preferable that the peak position of Pt.sub.3Co seen in the X-ray diffraction pattern of catalyst particles is 2=41.10 or more and 42.00 or less, and moderate alloying has occurred in the catalytic metal.

A method for improving the performance and/or stability of non-precious metal catalysts in fuel cells and other electrochemical devices. Improved membrane electrode assemblies (MEAs) and fuel cells containing the same are provided. Such MEAs include a catalyst layer made up of at least two sub-layers containing ionomers of differing equivalent weights. The sub-layers may optionally contain mixtures of ionomers. Also provided are methods of making and using the described devices.

A catalyst layer, includes: a carrier; metal particles located over the carrier; an underlayer located on the carrier; and an ionomer-based layer located over the underlayer, wherein the underlayer includes a polymer material, and covers at least parts of the metal particles, and the ionomer-based layer includes a proton-conducting resin. A fuel cell electrode includes the catalyst layer, and a fuel cell including the above catalyst layer. A method for producing a catalyst layer, includes: bringing at least one first solution including a polymer material into contact with a metal-particle-supported carrier to form an underlayer; and bringing a second solution including a proton-conducting resin into contact with the metal-particle-supported carrier to coat said metal-particle-supported carrier with the proton-conducting resin.

The electrochemical cell includes an anode, a cathode active layer, and a solid electrolyte layer disposed between the anode and the cathode active layer. The cathode active layer includes a first region which is disposed facing the solid electrolyte layer, and a second region which is disposed on the first region. An average particle diameter of first constituent particles which constitute the first region is smaller than an average particle diameter of second constituent particles which constitute the second region.

A membrane electrode assembly includes a pair of electrodes, each having a feeder layer that is porous and made of a conductive material, and an electrolyte membrane disposed between the pair of electrodes. At least one of the electrodes has a catalyst layer disposed in the feeder layer. In a cross section of the feeder layer, an electrolyte exists in a first region less than or equal to 80% of a thickness of the feeder layer from the electrolyte membrane toward an opposite direction to the electrolyte membrane, the catalyst layer exists at 50% or more of an outer circumference of a cross section of the conductive material in the first region, and the catalyst layer exists at 10% or less of the outer circumference of the cross section of the conductive material in a second region other than the first region.