MEMBRANE-ELECTRODE UNIT FOR POLYMER ELECTROLYTE FUEL CELLS AND PROCESSES FOR THEIR PREPARATION

摘要

The invention relates to a membrane-electrode unit for polymer-electrolyte fuel cells. The membrane-electrode unit consists of a polymer electrolyte membrane and porous reaction layers applied to both sides comprising a catalyst and a proton-conducting polymer, a so-called ionomer. The membrane-electrode unit is characterized in that one part Al of the catalyst of the reaction layers is saturated with the ionomer and is embedded in the ionomer whereas one part A2 of the catalyst is kept free from the ionomer, where the parts Al and A2 are in a weight ratio of 1:1 to 20:1.