Precise Ga engineering of surface reaction energetics in Pd2Sn for enhanced alcohol electrooxidation.

Abstract

Alcohol electrooxidation is an important anodic reaction in alkaline electrochemical energy-conversion systems, yet its performance is often limited by sluggish reaction kinetics and catalyst deactivation associated with strongly adsorbed intermediates. Herein, Ga was introduced into the Pd2Sn intermetallic to regulate its surface reaction energetics. A series of composition-controlled ternary Pd2(Sn1-xGax) intermetallic nanoparticles were synthesized through a ligand-regulated colloidal strategy. Systematic compositional optimization identified Pd2(Sn0.87Ga0.13) as the optimal catalyst, which exhibited enhanced catalytic activity, continuous operational stability, and electrochemical regenerability toward glycerol, methanol, and ethylene glycol oxidation in alkaline media. For glycerol oxidation, Pd2(Sn0.87Ga0.13) delivered a mass activity of 3.21 A mgPd-1 and a specific activity of 16.31 mA cm-2, while quantitative product analysis identified glyceric acid as the predominant liquid product. Density functional theory calculations suggest that Ga incorporation modifies the surface reaction energetics by strengthening hydroxyl adsorption and weakening glyceric acid binding, thereby facilitating intermediate conversion and product desorption. This work suggest that precise Ga engineering of Pd2Sn intermetallics can effectively tune surface reaction energetics and provide a viable strategy for improving the catalytic performance and resistance to deactivation of alkaline alcohol oxidation electrocatalysts.