Catalyst-containing gas diffusion layer for fuel cells and process for producing it

The invention relates to a gas diffuser substrate containing catalysts for fuel cells, especially low temperature fuel cells, such as PEMFC and DMFC. The gas diffuser substrate is used on the anode side of the fuel cell and contains catalyst components which result in the removal of carbon monoxide (in the PEMFC) and respectively the oxidation of methanol (in the DMFC). Said catalyst components are produced directly in porous substrate material by thermal treatment of suitable precursor compounds and are homogeneously distributed over the total volume of the gas diffuser substrate. As a result, the catalyst components have particularly high activity. The invention also relates to a method for the production of a gas diffuser substrate containing catalysts. The gas diffuser substrates used in membrane electrode units (MEEs) for low temperature fuel cells, especially for PEM-fuel cells, are operated with reformate gas containing CO. Said substrates are also used in direct-methanol-fuel cells (DMFC).