Nanoporous gold catalyst for direct ammonia borane fuel cells

Abstract

Nanoporous gold (NPG) electrodes were fabricated in film and wire array formats by selectively dealloying Ag from Au0.18Ag0.82. The ammonia borane (AB) oxidation reaction was studied by cyclic voltammetry at the NPG electrodes. The onset potential for the oxidation at NPG in a wire array format shifted to more negative potentials than that observed at a Au disc and higher currents were realised. An onset potential of -1.30 V vs. SCE was recorded which is 0.28 V lower than that at a Au disc. The oxidation current for 20 mM AB in 1 M NaOH increased from 2.65 mA cm(-2) at a Au disc to 13.1 mA cm(-2) at a NPG wire array. NPG is a viable candidate as an anode catalyst for a direct ammonia borane fuel cell.