Mechanistic study of the deactivation of carbon supported Pd during formic acid oxidation

Palladium is an attractive anode catalyst for direct formic acid fuel cells (DFAFC) because of its high activity relative to Pt, but it suffers significant activity losses during operation of the DFAFC. The deactivation mechanism of a Pd/C catalyst during oxidation of formic acid has been studied by means of electrochemical stripping voltammetry. The stripping characteristics of the anode poison are virtually the same as those of adsorbed CO, and adsorbed CO has a similar poisoning effect. It is therefore proposed that a gradual build-up of adsorbed CO causes the deactivation of Pd in DFAFCs. (C) 2009 Elsevier B.V. All rights reserved.