A nanoparticle catalyst with superior activity for electrooxidation of formic acid

This paper reports the synthesis and characterization of a series of Pt-based nanoparticle catalysts with high activity for formic acid electrooxidation. The catalysts were prepared using spontaneous deposition to decorate platinum nanoparticles with controlled amounts of palladium and pall adium/ruthenium. Among all the catalysts investigated, the Pt/Pd catalyst shows the best performance; the steady-state formic acid oxidation current is ca. 1 mA cm(-2) at 0.27 V vs. RHE, This current is two orders of magnitude higher than that obtained from pure platinum, and the catalyst is ideally suited to be an anode in the direct oxidation formic acid fuel cell. The enhancement in formic acid oxidation by the admetal addition does not correlate with the threshold for CO oxidative stripping (the CO tolerance). The Pt/Pd catalyst requires the highest potential to remove the CO, yet it is the most active. We suggest, therefore, that within the dual path mechanism of formic acid oxidation, the direct CO2 formation channel on Pt/Pd is much less affected by the CO chemisorption than on Pt, or on the Pt/Pd/Ru catalyst, also studied in this report. (C) 2002 Elsevier Science B.V. All rights reserved.