Heteroengineered Co3O4/CeO2 with Accelerated Electron Transfer and Enhanced Stability for Chlorine-Involved Anodic Reactions

Abstract Electrosynthesis of epoxides from alkenes represents a safe and sustainable strategy to replace conventional synthetic methods that require harsh conditions. However, its practical industrial application is greatly restricted by low current density, competitive oxygen evolution reaction (OER), and poor electrocatalyst stability. Herein, we constructed a Co3O4/CeO2 heterojunction electrocatalyst with enhanced activity and stability toward chlorine (Cl)-involved anodic reactions. Spectroscopic and electrochemical characterizations combined with theoretical calculations reveal that strong electronic coupling at the heterointerface drives directional electron transfer from CeO2 to Co3O4, accelerating electron transport and facilitating Cl– activation. Moreover, the compressed Co–O bond of Co3O4/CeO2 enhances the stability and thus breaks the activity/stability tradeoff. Under practical conditions (100 mA cm–2), Co3O4/CeO2 not only realizes the gram-scale electrosynthesis of cyclohexene oxide with high Faradaic efficiency but also is suitable for other chlorination reactions. Our study provides a heterojunction-engineering strategy to promote the electrooxidation activity for Cl-involved anodic reactions.