Improvement of Mesoporous Carbon Supports for PEFC

New mesoporous carbon (MC) bulk was developed and used as a cathode support, and then 45% Pt/new MC cathode was prepared. Current-voltage (IV) performance of a membrane electrode assembly (MEA) with 45% Pt/new MC cathode was much improved at the high current density area in comparison to a MEA with 33% Pt/conventional MC and also to a standard MEA. Reasons for this improvement were considered in this study. The increased ionomer/carbon (I/C) ratio in the cathode layer was found to be one of the factors for improving IV performance. Also, increase in Pt loading percent against the carbon support came to another factor, which lead to a thinner catalyst layer followed by reducing activation overvoltage and diffusion overvoltage. However, the most important factor for the improvement in the high current density area was found to be most likely the size of mesopores.