Among the various aspects of the present disclosure is the provision of method of inducing or providing a pH gradient in electrochemical or chemical systems. Briefly, the pH gradient is induced by use of coated particles or films with an ion exchange ionomer.

The invention relates to a method for producing a supported catalyst material for a fuel-cell electrode, as well as a catalyst material that can be produced using said method. In the method, first, a carbide-forming substance is deposited from the gas phase onto the carbon-based carrier material to produce a carbide-containing layer and, then, a catalytically-active precious metal or an alloy thereof from the gas phase is deposited to form a catalytic layer. By chemical reaction of the carbide-forming substance with the carbon, very stable carbide bonds are formed at the interface, while an alloy phase of the two forms at the interface between carbide-forming substance and precious metal. Overall, a very stable adhesion of the catalytic precious metal to the substrate results, whereby degradation effects are reduced, and the life of the material is extended.

The invention relates to a method for producing a supported catalyst material for a fuel-cell electrode, as well as a catalyst material that can be produced using said method. In the method, first, a carbide-forming substance is deposited from the gas phase onto the carbon-based carrier material to produce a carbide-containing layer and, then, a catalytically-active precious metal or an alloy thereof from the gas phase is deposited to form a catalytic layer. By chemical reaction of the carbide-forming substance with the carbon, very stable carbide bonds are formed at the interface, while an alloy phase of the two forms at the interface between carbide-forming substance and precious metal. Overall, a very stable adhesion of the catalytic precious metal to the substrate results, whereby degradation effects are reduced, and the life of the material is extended.

A fuel cell membrane electrode assembly having: a proton exchange membrane, an anode catalyst coating on one side of the membrane, and a cathode catalyst coating on the other side of the membrane. The cathode catalyst coating has at least two carbon catalyst layers, with a low porosity layer adjacent to a high porosity layer. The high porosity layers have a volume fraction that is higher than the volume fraction of the low porosity layers.

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.

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.

A cathode catalyst layer and an anode catalyst layer used for a membrane-electrode assembly in a polymer electrolyte fuel cell, wherein the cathode catalyst layer and the anode catalyst layer each include catalyst particles, a conductive carrier, a polymer electrolyte, and a fibrous material, the fibrous material includes at least one of an electron conductor and a proton conductor, and the fibrous material has a specific surface area in a range of 40 m.sup.2/g or more and 80 m.sup.2/g or less.

The present disclosure provides a preparation method of a catalyst slurry for a fuel cell membrane electrode assembly (MEA), including the following steps: preparing a slurry mixture with a catalyst, a dispersing solvent, an ionomer, a thickener, and a surfactant according to a certain mass ratio; subjecting the slurry mixture to pre-dispersion several times in an ultrasonic disperser and a high-shear emulsifying machine successively, to obtain a slurry pre-dispersion; and conducting dispersion on the slurry pre-dispersion in a high-pressure homogenizer to obtain the catalyst slurry. In the present disclosure, components of the catalyst slurry and a dispersion process are optimized and innovated, to construct a more effective three-phase interface. The MEA prepared according to the present disclosure has a significantly improved performance and reduced slurrying time; and is thus suitable for mass production.

Composites including silica phase and magneli-phase titanium suboxide, supported catalyst particles including the same, electrodes including the supported catalyst particles, and electrochemical cells including the electrode.

A dimeric ionic liquid that enhances and improves the performance and durability of a fuel cell catalyst. The dimeric ionic liquid comprises 1,1-(butane-1,4-diyl)bis(9-methyl-3,4,6,7,8,9-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-ium 1,1,2,2,3,3,4,4,4-nonafluorobutane-1-sulfonate (D-[MTBD][C.sub.4F.sub.9SO.sub.3]). Membrane electrode assemblies (MEAs) and polymer electrolyte membrane fuel cells (PEMFCs) employing the dimeric ionic liquid are also disclosed.