Proton exchange membrane fuel cells (PEMFCs) represent one of the most promising sustainable energy alternatives under development. However, their entry into the marketplace has been hindered by a number of operational factors, which must be addressed before widespread commercialisation is achieved. One of the foremost of these issues is the barrier to high temperature operation imposed by polymer electrolyte membranes, which are currently used as the proton conductors in PEMFCs. Dehydration and structural changes at temperatures greater than 100oC result in poor conductivity. However, a new class of inorganic proton conducting materials is drawing increasing amounts of attention as a possible alternative to polymer electrolyte membranes.
This research aims to explore a number of different synthesis and post-treatment methods for inorganic proton conductors, in the hopes of finding a material which can surpass Nafion, the industry standard, in terms of proton conductivity. Two samples of titanium phosphate (TIPO) were synthesised using a sol-gel method, incorporating
a surfactant template into one sample to improve the surface area. Silica gels (SIO2) were prepared via a two-step hydrolysis and condensation route, using surfacebased sulfonic acid groups to test the effect of functionalisation. Two ordered titanium-silicon hybrid oxides (TISI), one containing amino groups and one containing sulfonic acid groups, were synthesised using a surfactant template. Sample were subjected to a range of heat treatment temperatures, as well as a thorough washing procedure to ensure their stability.