Convergent Electrochemical–Chemical Tandem Catalysis Synthesis of Ethylene Oxide from CO₂ and Water at Ambient Conditions

Abstract

AbstractEthylene oxide (EO) is an important commodity chemical, and its production currently relies on fossil fuel‐based energy‐intensive thermocatalysis associated with substantial CO2 emissions or the usage of toxic/corrosive precursors (e.g., Cl2). Herein, we report a convergent electrochemical–chemical tandem route for efficient synthesis of EO from CO2 and water under ambient conditions over nonprecious catalysts. Such a protype consists of cathodic CO2 electroreduction to C2H4 and simultaneous anodic two‐electron water electrooxidation (2e‐WOR) to H2O2 in a single electrolyzer, followed by reaction of the two products over titanium silicalite‐1 (TS‐1) catalyst toward EO with high production rate of 422.3 µmol h−1 and high selectivity of >98%. W‐doped CuOx and Cu‐doped SnO2 were used as cathode and anode electrodes with respective Faradaic efficiencies of 63.5% and 75.6% at 800 mA cm−2. Systematic characterizations, including 119Sn Mössbauer spectroscopy, quasi‐in situ electron paramagnetic resonance (EPR), isotope‐labeling mass spectrometry (MS), and operando infrared spectroscopy, along with theoretical calculations, reveal that Cu doping breaks the electronic structure symmetry of Sn to induce electron redistribution for optimal adsorption and coupling of key intermediates like *OH in 2e‐WOR. This study offers a sustainable manner for efficient EO synthesis from raw materials with renewable electricity input.