Efficient electro-oxidation of formic acid at Pd-MnOx binary nanocatalyst: Optimization of deposition strategy

Abstract

Formic acid (FA) electro-oxidation (FAO) was investigated at a binary catalyst composed of Pd (nano-Pd) and manganese oxide (nano-MnOx) nanostructures assembled onto a glassy carbon (GC) electrode. The deposition strategy of the catalyst components is properly adjusted in such a way that could eventually improve its electrocatalytic activity and stability toward FAO. The highest catalytic activity and stability are obtained at the Pd-MnOx/GC electrode (for which nano-Pd and nano-MnOx were simultaneously deposited onto the GC electrode). Such enhancement is thought to originate from facilitating the direct oxidation of FA and/or minimizing the adsorption of poisoning species at the electrode surface. Herein, several techniques including cyclic voltammetry, chronoamperometry, electrochemical impedance spectroscopy, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction are used to track the catalyst activity and to reveal its surface morphology and composition.