The use of a PtAu catalyst as an anode catalyst for the oxidation of formic acid in direct formic acid fuel cells is described. Catalytic activities of PtAu and PtRu anodes were studied using a linear sweep voltammetry technique in a single cell configuration. PtAu showed a lower on-set potential and a larger current density than that of PtRu in formic acid oxidation. In addition, the maximum power densities at 30 degrees C for PtAu and PtRu were 94 and 74 mWcm(-1), respectively. In order to evaluate long-term durability, the single cells were operated for hundreds of hours with a 6 M aqueous formic acid solution at 60 degrees C under 100 mA cm(-2). The difference in performance between PtAu and PtRu after 500 h reached ca. 90 mV in direct formic acid fuel cells. (c) 2006 Elsevier B.V. All rights reserved.