Boosting electrocatalytic oxidation of formic acid on SnO2-decorated Pd nanosheets

Abstract

Formic acid (HCOOH), as a natural biomass, is a promising feedstock for low temperature fuel cells, and rational development of efficient catalysts for electrochemical dehydrogenation of HCOOH plays a key role toward its full chemical energy utilization. Herein, Pd nanosheets decorated with SnO2 nanoflakes (denoted hereafter as Pd@SnO2-NSs) are designed as a composite catalyst, showing superior performance for formic acid electro-oxidation, as compared to pristine Pd nanosheets (Pd-NSs). In situ attenuated total reflection infrared (ATR-IR) spectroscopic results suggest a promoted formate pathway on the Pd@SnO2-NSs with a suppressed accumulation of CO poisoning species. DFT calculations further indicate that the Pd (111) surface modified with SnO2 has lower energy barriers for the bidentate formate formation, the bidentate to monodentate formate transformation and the C-H bond scission.