Electrodeposited palladium nanostructure as novel anode for direct formic acidfuel cell

Abstract

A novel membrane electrode assembly (MEA) structure for direct formic acid fuel cell (DFAFC) has been designed. The novelty is that Pd nanothorns are directly electrodeposited onto the carbon paper to form the anode catalyst layer. The Pd nanothorns are formed by a two step square wave electrodeposition. The dispersion and morphology of the Pd nanothorns on the carbon paper are observed by scanning electron microscopy (SEM). The crystal characteristics of the Pd nanothorns are studied by high resolution transmission electron microscopy (HRTEM) and the metallic property of the deposited Pd nanothorns is investigated by X-ray photoelectron spectroscopy (XPS). MEA is prepared with the Pd nanothorn covered carbon paper. The novel MEA provides 2.4 times higher peak power density than the conventional MEA. This increase in the performance is due to the improved mass transport of formic acid in the catalyst and diffusion layers, better Pd utilization and higher electroactivity of the Pd single crystal nanothorns.