Achieving over 90% Faradaic Efficiency in Cyclohexanone Oxime Electrosynthesis Using the Cu–Mo Dual-Site Catalyst

Abstract

Coupling with the nitrate electroreduction reaction (NitRR), the electrosynthesis of cyclohexanone oxime (CHO, the vital feedstock in the nylon-6 industry) from cyclohexanone provides a promising alternative to the traditional energy consumption process. However, it still suffers from low efficiency because selective production of *NH₂OH intermediate from NitRR under large current densities is challenging. We here report a Cu₁MoO_x/nitrogen-doped carbon (NC) electrocatalyst with high-density Cu–Mo dual sites for NitRR to selectively produce and stabilize *NH₂OH, with the subsequent cyclohexanone oximation achieving the highest CHO Faradaic efficiency of 94.5% and a yield rate of 3.0 mol g^–1 h^–1 at an industrially relevant current density of 0.5 A cm^–2. Furthermore, in situ characterizations evidenced that the Cu–Mo dual sites in Cu₁MoO_x/NC effectively inhibited hydrodeoxygenation of hydroxyl-containing intermediates of NitRR, selectively producing *NH₂OH and thus achieving cyclohexanone oximation with high efficiency. This work provides a high-performance catalyst for CHO electrosynthesis from nitrogenous waste, showing promising application potential in industrial production of CHO.