Atomically Asymmetrical Ir-O-Co Sites Enable Efficient Chloride-Mediated Ethylene Electrooxidation in Neutral...

The chloride-mediated ethylene oxidation reaction (EOR) of ethylene chlorohydrin (ECH) via electrocatalysis is practically attractive because of its sustainability and mild reaction conditions. However, the chlorine oxidation reaction (COR), which is essential for the above process, is commonly catalyzed by dimensionally stable anodes (DSAs) with high contents of precious Ru and/or Ir. The development of highly efficient COR electrocatalysts composed of nonprecious metals or decreased amounts of precious metals is highly desirable. Herein, we report a modified Co₃O₄ with a single-atom Ir substitution (Ir₁/Co₃O₄) as a highly efficient COR electrocatalyst for chloride-mediated EOR to ECH in neutral seawater. Ir₁/Co₃O₄ achieves a Faradaic efficiency (FE) of up to 94.8 % for ECH generation and remarkable stability. Combining experimental results and density functional theory (DFT) calculations, the unique atomically asymmetrical Ir-O-Co configuration with a strong electron coupling effect in Ir1/Co₃O₄ can accelerate electron transfer to increase the reaction kinetics and maintain the structural stability of Co₃O₄ during COR. Moreover, a coupling reaction system integrating the anodic chloride-mediated and cathodic H₂O₂-mediated EOR show a total FE of ~170 % for paired electrosynthesis of ECH and ethylene glycol (EG) using ethylene as the raw material. The technoeconomic analysis highlights the promising application prospects of this system.