Pulsed-Electrolysis-Induced Bi-Bi2O3 Transformation Switches the Reaction Pathway for Enhanced Cyclohexanone Oxime Production
Cyclohexanone oxime (CHO) is a pivotal feedstock for nylon-6 production, yet conventional synthesis routes suffer from high explosion risks, harsh conditions, and costly catalysts. Here, we report an electrocatalytic approach for CHO synthesis via reductive coupling of cyclohexanone (CYC) with nitrite over commercially available Bi2O3. A two-stage pulsed electrolysis protocol is employed: the first stage prepares amorphous Bi2O3, while the second stage produces CHO with a Faradaic efficiency (FE) of 74.63% and a yield rate of 0.156 mmol h−1 cm−2. Mechanistic studies, combining experiments and density functional theory (DFT) calculations, reveal that on amorphous Bi2O3, the *NOH intermediate preferentially undergoes hydrogenation to *NHOH and then *NH2OH, rather than the *NOH→*N pathway leading to NH3. This selectivity is attributed to the higher integral crystal orbital Hamilton population (ICOHP) for the N–O bond in *NOH on amorphous Bi2O3 (1.34 vs. 0.84 on amorphous Bi), indicating a weakened N–O bond that facilitates hydrodeoxygenation. Transition state calculations show a kinetic barrier of 0.86 eV for *NH2OH→*NH2, while desorption of *NH2OH to NH2OH is barrierless, favoring NH2OH release. This work provides a sustainable, efficient alternative to conventional CHO production, addressing safety and cost concerns while achieving high selectivity.