Platinum ionomer composite films

The complex interface between polymer electrolytes and nanostructured electrodes is key for the operation of many electrochemical devices. While the surface science of electrocatalysts have been extensively studied using simplified model systems, such as Pt single crystals, the extent to which lessons from these models apply to nanostructured interfaces remains poorly understood. In this work, the interface between Pt nanoparticles and solid polymer electrolytes is explored in terms of catalytic activity, morphology and durability. The nucleation and growth of nanoparticles is controlled to produce contiguous ultrathin catalyst layers in a solution processable fashion using electroless deposition. The reactivity and structure of the Pt-polymer surface was probed with advanced characterization techniques using synchrotron radiation. Direct imaging of the solid-electrolyte-interphase was accomplished with X-ray spectromicroscopy. Degradation of this interface was visible after a simulated aging protocol. Finally, the mechanism of surface oxidation and reduction on Pt nanoparticles was explored with diffraction, moving towards an atomistic understanding of fuel cell electrochemistry inside functional devices under relevant operational conditions.Science, Faculty ofChemistry, Department ofGraduat