A Bipolar Integrated Electro‐Chemocatalysis System for Continuous‐Flow Paired Synthesis of Cyclohexanone Oxime at Industrial‐Relevant Current Density

Abstract

ABSTRACT ε‐Caprolactam production critically depends on cyclohexanone oxime (CHO), yet its sustainable synthesis remains constrained by the handling and utilization of hydrogen peroxide (H 2 O 2 ). Here, we developed a bipolar integrated electro‐chemocatalysis system (BIECS) that enables continuous‐flow paired CHO synthesis under ambient conditions with unprecedented efficiency. Using oxygen‐vacancy‐enriched bismuth oxide nanofibers as a bifunctional electrocatalyst, the system simultaneously drives the two‐electron oxygen reduction and water oxidation reactions at the cathode and anode, respectively, achieving remarkable cell Faradaic efficiencies up to 165% for H 2 O 2 production, which then on‐site reacts with cyclohexanone and NH 3 over titanium silicon‐1 with near‐unity selectivity. Consequently, the BIECS delivers remarkable apparent electron efficiency of 120%–160% for cascade CHO production and achieves an exceptional productivity of up to 5.04 mmol h −1 cm −2 at industrial‐relevant current density with excellent stability over 150 h for continuous‐flow electrolysis. Combined experimental and theoretical studies reveal that the oxygen vacancies of the catalyst modulate the adsorption energetics and configuration of the key OOH * intermediate, thereby promoting highly selective two‐electron pathways at both electrodes and enhancing the cascade ammoximation kinetics. This work establishes a scalable strategy that integrates paired electrocatalytic H 2 O 2 synthesis with chemocatalytic ammoximation, providing a highly efficient platform for sustainable CHO production.