High Performance plasma sputtered PdPt fuel cell electrodes with ultra low loading

A PdPt (10 wt% Pt) catalyst is used to replace platinum at the cathode of a proton exchange membrane fuel cell membrane electrode assembly (PEMFC MEA) whereas pure palladium is used as the anode catalyst. The catalysts are deposited on commercial carbon woven web and carbon paper GDLs by plasma sputtering. The relations between the depth density profiles, the electrode support and the fuel cell performances are discussed. It is shown that the catalyst gradient is an important parameter which can be controlled by the catalyst depth density profile and/or the choice of electrode support. An optimised electrode structure has been obtained, which allows limiting the platinum requirement. Under suitable conditions of a working PEMFC (80 °C and 3 bar absolute pressure), very high catalysts utilization is obtained at both electrodes, leading to 250 kW gPt−1 and 12.5 kW gPd−1 with a monocell fitted with a PdPt (10:1 weight ratio) cathode and a pure Pd anode.