In this presentation we describe a strategy to molecularly optimize the cathode side of a proton exchange membrane fuel cell. This new cathode consists of a porous alumina membrane with metal-lined pores that function as gas diffusion conduits while supporting a catalyst layer and ionomer. The ionomer chains are grown from the surface of the pore walls and are designed to encapsulate the catalyst particles to provide a well-defined three-phase boundary for gas, proton, and electron transfer. Two new classes of ionomer are evaluated, including non-fluorinated and partially fluorinated polymers prepared by the surface-initiated ring-opening metathesis polymerization (ROMP) of a functionalized norbornene and subsequent sulfonation with acetyl sulfate. These ionomers are grown rapidly and conformally over any surface geometry with nanometer-level control over thickness. The effectiveness of a high-utilization catalyst attachment method is demonstrated through electrochemical monitoring of the oxygen reduction reaction.

Extended Abstract Status: Not Uploaded