Concurrent Electrosynthesis of Formate and Hydrogen Peroxide by Manipulating Interfacial Charge Distribution and Oxygen Vacancy

ABSTRACT Electrochemical carbon dioxide reduction reaction (CO ₂ RR) coupled with two‐electron water oxidation reaction (2e ⁻ WOR) is a promising yet challenging route for simultaneous production of formate and hydrogen peroxide. Herein, we propose a paired electrochemical system for the selective coproduction of formate and hydrogen peroxide based on SnS ₂ ‐derived catalysts on both anode and cathode. The cathode loaded with Bi/Sn heterostructure upon electrochemical activation achieves maximum Faradaic efficiency of 97.7% for formate and maintains above 90% across a wide potential window of 1000 mV, while the anode leverages electrochemically activated SnO ₂ with abundant oxygen vacancies to catalyze 2e ⁻ WOR with Faradaic efficiency of 69.8% toward hydrogen peroxide formation. Experimental and theoretical analyses reveal that the Bi/Sn upon interfacial charge redistribution demonstrates reduced energy barriers during CO ₂ RR. The presence of oxygen vacancies in SnO ₂ facilitates the coupling of *OH intermediates to promote hydrogen peroxide formation. The present findings provide critical insights into designing high‐performance electrocatalysts derived from shared precursors to coproduce valuable chemicals.