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

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.