The methanol crossover, which methanol diffuses from anode to cathode, is the major hurdles that prevent direct methanol fuel cell (DMFC) from becoming a commercial product. The methanol crossover degrades the fuel efficiency and reduces the performance of cathode catalyst. Therefore, the approach is to develop a catalyst which catalyzes the oxygen reduction reaction (ORR) but insensitive to the presence of methanol.
In this study, we used carbon (XC-72) supported cobalt tetra-methoxyphenyporphyrin (CoTMPP/C) as the cathode catalyst. The electrochemical behavior of CoTMPP/C that investigated by polarization of the rotating disk electrode (RDE) was similar to that of Pt/C. The CoTMPP/C, which including 20 wt.% and 163 μg/cm^2 of CoTMPP, prepared by heat treatment at 700℃ shows the best ORR performance and methanol tolerance. For investigating the enhanced behavior, XPS, FTIR, and TG-DTA were employed to characterize COTMPP/C. The formation of Co-N(subscript x)-C(subscript y) and β-Co were observed from above characterizations. We believed that this is the reason that resulting in the increase of ORR performance, but suppressing the methanol oxidation reaction.