Electro-oxidation of methanol and formic acid on PtRu and PtAu for direct liquid fuel cells

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 °C for PtAu and PtRu were 94 and 74 mW cm−2, 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 °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.