Dispersing Pt atoms onto nanoporous gold for high performance direct formic acid fuel cells

Abstract

Direct formic acid fuel cells (DFAFCs) are promising portable energy conversion devices for supplying our off-grid energy demands. However, traditional Pt-based catalysts suffer from poor performance; consequently the precious metal loading in an actual fuel cell has to be maintained at a very high value, typically orders of magnitude higher than the acceptable level. Through a molecular self-assembly/electro-deposition process, Pt atoms are effectively dispersed onto the surface of a nanoporous gold substrate, and the resulting nanocomposites demonstrate superior electrocatalytic performance toward formic acid electro-oxidation, which can be attributed to a nearly ideal catalyst configuration where all the Pt atoms are involved in a highly desired direct reaction path. In both half-cell electrochemical testing and actual DFAFCs, these rationally designed electrodes show over two orders of magnitude improvement in Pt efficiency, as compared with the state-of-the-art Pt/C catalyst. This design strategy allows customized development of new generation electrocatalysts for high performance energy saving technologies.