Development of Mesoporous Carbon Fibers As Catalyst Supports for PEFC

Mesoporous carbon fiber (MCF) sheet was developed for the purpose of controlling both the macroscopic fiber structure and the mesopore structure of the fibers. Two types of MCF sheet electrodes were fabricated by changing the conditions of the solution of electrospining. By depositing Pt on MCF sheet followed by introducing Nafion ionomer, MEAs with Pt/MCF sheet electrode as the cathode were prepared, and their IV performance was evaluated. As a result, Pt/MCF sheet electrodes successfully functioned as cathodes. On the other hand, IV performance was lower than that of a standard MEA, mainly due to the higher activation and concentration overvoltage. After evaluating different Pt/MCF sheet MEAs, increase in the Pt loading per sheet volume was found to be important to reduce the activation overvoltage, and optimizing the fiber density within the MCF sheet was found to be important to reduce the concentration overvoltage.