Catalyst Coated PBI Membrane High Temperature Assemblies

A route has been developed to stabilise a polybenzimidazole gel membrane formed in polyphosphoric acid by simultaneous cross-linking. With increasing degrees of cross-linking the mechanical properties of the high acid content PBI membranes are significantly improved, while the phosphoric acid content and the membrane conductivity are not greatly affected. PBI/H3PO4 membranes are generally integrated into an assembly using gas diffusion electrodes. In the present work, cross-linked PBI membranes have been used as substrates for catalyst coated membrane preparation using a Pt/C catalyst transferred by decal to the membrane surfaces. The final membrane electrode assemblies have been characterized for their high temperature performance and durability.