(600p) Comparative Study of Direct Methanol Fuel Cell Anode Catalysts

The success of direct methanol fuel cell (DMFC) technology depends largely on the electro-catalyst. Currently, Pt-Ru alloy catalysts are most popular choice for DMFC anode due to their effective methanol oxidation reaction.  However, fuel cell performance can be significantly damaged by ruthenium leaching, which not only removes the active component in the anode, but also contaminates the cathode catalyst. Therefore, anode catalyst with high metal dispersion and ruthenium leaching resistance is of great interest for excellent fuel cell performance. In this research, synthesized Pt-Ru metal alloy based anode catalysts were compared with commercially available Pt-Ru based DMFC anode catalysts. The synthesis and commercial catalysts were characterized by various surface techniques, to obtain information, such as particle morphology and catalyst composition before and after degradation. The methanol oxidation performance was assessed by cyclic voltammetry for all anode catalysts. The durability of anode catalysts was measured by accelerated cyclic voltammetry in half cell. Also, commercial anode catalysts was integrated in a single cell DMFC with a novel open-cathode design utilizing a liquid barrier layer (LBL), and a low-voltage accelerated degradation method was employed to purposely induce anode degradation in all commercial anode catalysts. It was found that two anode catalysts from Johnson Matthey Co. demonstrated higher anode activity than the two anode catalysts from Tenaka and Cabot. Of the two Johnson Matthey catalysts, the stabilized DMFC anode catalyst exhibited slightly lower anode activity, but had a much better degradation resistance compared with the standard DMFC anode catalyst.