Leaching tolerance of anodic Pt-based intermetallic catalysts for formic acid oxidation

The leaching tolerance of Pt-based intermetallic compounds both in the form of bulk and nanoparticle (NP) in the oxidation reactions of formic acid (FA) in acidic media was examined. The intermetallic PtPb showed the most promising electrocatalysts among the examined bulk intermetallics in terms of the onset potential as well as the stable oxidation current density toward FA oxidation. The intermetallic PtPb electrode showed the superior catalytic activity toward FA oxidation than a Pb-adatom modified Pt electrode. The leaching tolerance was improved through the formation of an intermetallic phase between Pt and Pb. The degradation rate of PtPb and PtBi electrodes in the oxidation current density is lower than that of a Pt and other tested intermetallic electrodes. The stability of the oxidation current density of FA was strongly depended on the leaching of the constituent elements of the intermetallic compounds. The constant electric potential treatment over intermetallic electrodes at relatively higher potential altered the composition and crystal structure due to the leaching of the constituent elements.