Carbon-coated carbon black as stable electrocatalyst support for polymer electrolyte membrane fuel cells.

Abstract

The surface of commercial carbon black was modified by pyrolysis of acetonitrile in attempt to obtain the graphitic carbon coating layer. It was confirmed that the surface of carbon black was partially graphitized, having 0.23 of graphitization index and 1.87 nm of mean stack height. From the electrochemical oxidation test of carbon, the carbon-coated carbon black showed higher corrosion resistance than the untreated carbon black although the core of the carbon black support still remained untreated. When it was applied to the support for platinum electrocatalyst, the enhanced stability was observed. From those corrosion tests as well as XPS results, it can be suggested that the partially crystalline graphitic carbon surface facilitates the relatively more reduced surface of platinum.