Performance characterization of Pd/C nanocatalyst for direct formic acid fuel cells

Previous work has demonstrated that unsupported Pd (Pd black) based direct formic acid fuel cells (DFAFCs) show unusually high power density at the ambient temperature. In this paper finely dispersed Pd particles have been deposited on carbon supports (Vulcan XC-72 (R)). In particular, both 20 and 40 wt.% Pd on carbon supports (Pd/C) nanocatalysts have been synthesized and their performances, as an anode catalyst for DFAFC, with different formic acid feed concentrations at a moderate temperature have been evaluated. The 20 and 40 wt.% Pd/C based DFAFCs, with dry air and zero backpressure, can generate a maximum power density of 145 and 172 mW cm(-2) at 30 degrees C, respectively. Their open cell potentials are 0.90 V. In comparison to the unsupported Pd, we found that the 20 wt.% Pd/C in the DFAFC shows a lower total current, but a higher current per gram of precious metal than the Pd black catalyst. The supported catalysts also show less deactivation at the high formic acid concentrations. (c) 2005 Published by Elsevier B.V.