Advances in Direct Formic Acid Fuel Cells: Fabrication of Efficient Ir/Pd Nanocatalysts for Formic Acid Electro-Oxidation

Abstract

The modification of a glassy carbon (GC) electrode with palladium (PdNPs) and Iridium (IrNPs) nanoparticles is targeted to develop efficient anodes for formic acid electro-oxidation (FAO). The deposition order of PdNPs and IrNPs is appropriately adjusted in such a way that could improve the electrocatalytic activity and stability of the electrode towards FAO. The highest catalytic activity and stability are obtained at the Ir/Pd/GC electrode (with PdNPs directly deposited onto the GC electrode followed with IrNPs). Such enhancement is manifested in the increase of the oxidation current of formic acid (FA) together with a favorable negative shift in the onset potential of FAO. This marvelous enhancement is believed to originate from the electronic enhancement and/or the bi-functional mechanism of IrNPs to the Pd–based catalysts.