IMPROVED MEMBRANE ELECTRODE ASSEMBLIES FOR PEM FUEL CELLS

摘要

The invention relates to Membrane Electrode Assemblies ("MEAs") for solid- polymer-electrolyte proton-conducting membrane fuel cells ("PEM-FCs") having better performance and improved durability, in particular when operated under severe electro-chemical conditions such as fuel starvation and start-up/shut-down cycling. The MEAs are characterized in that at least one of its two electrode layers (EL and/or EL2) contains a first electrocatalyst (EC1) comprising an iridium oxide component in combination with at least one other inorganic oxide component anda second electrocatalyst (EC2/EC2'), which is free from iridium. Preferably, an iridium oxide/titania catalyst is employed as EC1. The MEAs reveal better performance, in particular when operated under severe operating conditions such as fuel starvation and start-up/shut-down cycling.