Proton-Conducting Polynorbornene Films for Fuel Cell Applications

Proton Exchange Membrane(PEM) fuel cells are an environmentally friendly alternative power source. However, current fabrication methods of PEM fuel cells are highly empirical and irreproducible, leading to expensive wastes and making comparisons between laboratories difficult. The research presented herein seeks to molecularly redesign and optimize the PEM-catalyst interface through the use of surface initiated ring-opening metathesis polymerization(SI-ROMP). The employment of surface-initiated polymerization of ionomer films from the electrode surface offers the advantages of uniform coverage throughout complex electrode architectures and precise tailoring of the catalyst/ionomer interface. Norbornene and its butyl, hexyl, and decyl substituted derivatives can be polymerized from a gold plated silicon surface via ROMP. A major component of this new PEM fuel cell design is the role of the ionomer film in the structuring of the entire fuel cell architecture. Transport at the catalyst interface is optimized as the norbornene backbone of the film permits gas diffusion and provides structure to the film, while sulfonate groups form proton-conducting channels.