MEMBRANE ELECTRODE ASSEMBLIES WITH HYDROGEN PEROXIDE DECOMPOSITION CATALYST

摘要

A membrane electrode assembly includes an anode including a hydrogen oxidation catalyst; a cathode; a membrane disposed between the anode and the cathode; and a peroxide decomposition catalyst positioned in at least one position selected from the group consisting of a layer between the anode and the membrane and a layer between the cathode and the membrane wherein the peroxide decomposition catalyst has selectivity when exposed to hydrogen peroxide toward reactions which form benign products from the hydrogen peroxide. The peroxide decomposition catalyst can also be positioned within the membrane. Also disclosed is a power-generating fuel cell system including such a membrane electrode assembly, and a process for operating such a fuel cell system. The assembly components contain ionomer material which can be perfluorinated or non-perfluorinated, high temperature, hydrocarbon, and the like.

主权项

1. A membrane electrode assembly, comprising:
an anode including a first hydrogen oxidation catalyst; a cathode; a membrane disposed between said anode and said cathode; and a peroxide decomposition catalyst positioned in a first porous layer between said anode and said membrane and in a second porous layer between said cathode and said membrane, wherein said peroxide decomposition catalyst has selectivity when exposed to hydrogen peroxide toward reactions which form benign products from said hydrogen peroxide, and wherein said first and second porous layers each have a porosity of greater than 0% and less than or equal to about 20%, wherein the porosity of the first and second porous layers is less than that of the anode and the cathode, and wherein at least one of said anode, cathode, membrane, first porous layer, and second porous layer includes perfluorinated polymer electrolyte ionomer material, wherein the first porous layer is separate from the anode, the first hydrogen oxidation catalyst comprises platinum and the peroxide decomposition catalyst comprises an element selected from the group consisting of Ir, C, Ag, Au, Sn, Si, Ti, Zr, Al, Hf, Ta, Nb, and Ce, the peroxide decomposition catalyst constitutes between about 5% and about 50% of the first porous layer by volume, and the anode includes a hydrophobic porous anode catalyst layer including the first hydrogen oxidation catalyst and the first porous layer is hydrophilic.