Preparation of a direct methanol fuel cell tubular cathode support from mesocarbon microbeads and graphite

A tubular cathode support green body for tubular direct methanol fuel cell was prepared by a gel casting molding method using a mixture of mesocarbon microbeads and natural graphite powder with a mass ratio of 3∶2 as carbon precursor. It was sintered at 1 000 ℃ for 5 h in a graphite boat covered by graphite powder. Subsequently, a tubular cathode and a planar anode were obtained by coating the supports with slurry containing a catalyst and a Nafion membrane in a PTFE suspension. The catalysts for the cathode and anode are Pt/C and Pt-Ru/C, respectively. Results show that the surface of the tubular cathode support is smooth with no distortion. Both the gas diffusion layer and catalyst layer of the cathode show a similar porous structure with most of the holes in the sub-micron scale, which is favorable for decreasing mass transfer resistance and improving catalytic efficiency. A single cell performance test indicates that the sintered cathode bodies from the mixture of mesocarbon microbeads and graphite can be used as a special-shaped cathode support.