PEM water electrolyzers: From electrocatalysis to stack development

Proton Exchange Membrane (PEM) water electrolysis can be used to produce hydrogen from renewable energy sources and can contribute to reduce CO2 emissions. The purpose of this paper is to report on recent advances made in PEM water electrolysis technology. Results obtained in electrocatalysis (recent progresses made in low-cost electrocatalysis offer new perspectives for decentralized and domestic applications), on low-cost membrane electrode assemblies (MEAs), cell efficiency, operation at high current density, electrochemical performances and gas purity issues during high-pressure operation, safety considerations, stack design and optimization (for electrolyzers which can produce up to 5 Nm3 H2/h) and performance degradations are presented. These results were obtained in the course of the GenHyPEM project, a 39 months long (2005–2008) research program supported by the European Commission. PEM technology has reached a level of maturity and performances which offers new perspectives in view of the so-called hydrogen economy.