A direct isopropanol fuel cell adapted for use in ambient conditions and utilizing as fuel isopropanol and water preferably with isopropanol at relatively high concentrations representing 30% to 90% isopropanol.

The present invention relates to stable catalyst ink formulations comprising am electrospinning polymer selected from halogen-comprising polymers. The present invention further relates to electrospinning of such ink formulation, to the so-obtained electrospun fibrous mat as well as to articles comprising such electrospun fibrous mat.

A method for manufacturing a membrane-electrode assembly for a fuel cell comprises the following steps: a first step during which a chemical catalyst element is deposited on a first face of an ion-exchanging membrane, the membrane being held on a support film; a second step during which the membrane is unglued from the support film; a third step during which the membrane is inserted between two reinforcing elements; and a fourth step during which a chemical catalyst element is deposited on the part left free of the second face of the membrane.

A catalyst layer (20) for a fuel cell and to a method suitable for producing the catalyst layer (20). The catalyst layer (20) includes a catalyst material (22) containing a catalytic material (24) and optionally porous carrier material (23) on which the catalytic material (24) is supported. The catalyst layer also includes mesoporous particles (21) made from hydrophobic material.

The present invention concerns a method for preparing a catalyst coated membrane including the steps of: coating a substrate with a first catalyst dispersion thereby obtaining a first catalyst dispersion coated substrate, providing a second side of a membrane with a support film, coating a first side of the membrane with a second catalyst dispersion, thereby obtaining a second catalyst dispersion coated first side of the membrane, drying the first catalyst dispersion thereby obtaining a first catalyst coated substrate or drying the second catalyst dispersion coated first side of the membrane thereby obtaining a second catalyst coated first side of the membrane, laminating the first catalyst coated substrate to the second catalyst dispersion coated first side of the membrane or laminating the first catalyst dispersion coated substrate to the second catalyst coated first side of the membrane so that the first catalyst and the second catalyst superimpose, thereby forming a laminate including a membrane comprising a first catalyst layer, drying the laminate, removing the support film from the second side of the membrane, coating a third catalyst dispersion on the second side of the membrane, drying the third catalyst dispersion, thereby obtaining a second catalyst layer on the membrane, and removing the substrate from the first catalyst coated substrate.

A method of manufacturing a membrane electrode assembly, includes: forming catalyst coated membrane using an electrode catalyst layer containing an ionomer having a sulfonic acid group and a catalyst carrier, and an electrolyte membrane; applying an ionization accelerator having a low molecular weight component represented by a chemical formula C.sub.lH.sub.mO.sub.n (where l, m, and n are natural numbers) for accelerating generation of sulfate ions, to the catalyst coated membrane; performing UV irradiation on the ionization accelerator applied to the catalyst coated membrane; heating the catalyst coated membrane having the ionization accelerator subjected to the UV irradiation; and bonding a gas diffusion layer containing a radical inhibiting substance to an outer surface of at least one of the ionization accelerator subjected to the UV irradiation or the catalyst coated membrane.

In this fuel cell electrode catalyst layer, a catalyst is supported on a carrier comprising inorganic oxide particles. The fuel cell electrode catalyst layer is provided with a porous structure. When a mercury penetration method is used to measure the pore size distribution of the porous structure, a peak is observed in the range spanning from 0.005 μm to 0.1 μm inclusive, and a peak is also observed in the range spanning from over 0.1 μm to not more than 1 μm. When P1 represents the peak intensity in the range spanning from 0.005 μm to 0.1 μm inclusive, and P2 represents the peak intensity in the range spanning from over 0.1 μm to not more than 1 μm, the value of P2/P1 is 0.2-10 inclusive. It is preferable that the inorganic oxide be tin oxide.

A porous carbon sheet contains carbon fiber and a binder, wherein the carbon sheet is characterized in that in a section from a plane having a 50% filling ratio closest to one surface to a plane having a 50% filling ratio closest to the other surface, when letting layer X be a layer with the largest filling ratio close to the one surface, layer Y be a layer with a filling ratio smaller than layer X close to the other surface, and layer Z be the layer positioned between layer X and layer Y for layers obtained by dividing the carbon sheet equally into three in a direction perpendicular to the surfaces, the filling ratio for the layers becomes smaller in order of layer X, layer Y, and layer Z.

A gas diffusion electrode is provided that enables the achievement of a fuel cell which has high drainage performance and maintains good power generation performance, while exhibiting high power generation performance particularly at a low temperature (40° C.), if used in the fuel cell. The gas diffusion electrode includes a microporous layer on at least one surface of a conductive porous substrate, wherein the microporous layer has a fluorine compound region having a length of 3-10 μm and a void having a length of 3-10 μm.

A membrane electrode assembly comprises an anode electrode comprising an anode catalyst layer and an anode gas diffusion layer, a cathode electrode comprising a cathode catalyst layer and a cathode gas diffusion layer, a polymer electrolyte membrane interposed between the anode catalyst layer and the cathode catalyst layer, and a layer comprising a fluoroalkyl-phosphonic acid compound between at least one of the anode gas diffusion layer and the anode catalyst layer, the anode catalyst layer and the polymer electrolyte membrane, the polymer electrolyte membrane and the cathode catalyst layer, and the cathode catalyst layer and the cathode gas diffusion layer.