Electrosynthesis of the Nylon-6 Precursor from Nitrate and Cyclohexanone over a Rutile TiO 2 Catalyst

Open AccessCCS ChemistryRESEARCH ARTICLES4 Apr 2024Electrosynthesis of the nylon-6 precursor from nitrate and cyclohexanone over a rutile TiO2 catalyst Lan Luo, Lingxiu Li, Liang Xu, Yifan Yan, Shanshan Zhang, Hua Zhou, Zhenhua Li, Mingfei Shao and Xue Duan Lan Luo , Lingxiu Li , Liang Xu , Yifan Yan , Shanshan Zhang , Hua Zhou , Zhenhua Li , Mingfei Shao and Xue Duan https://doi.org/10.31635/ccschem.024.202403988 SectionsSupplemental MaterialAboutPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareFacebookTwitterLinked InEmail Electrocatalytic reduction of nitrate (NO3−) to valuable organonitrogen compounds beyond ammonia is a promising strategy for mitigating the human-caused unbalance of the global nitrogen-cycle. Herein, we present an electrochemical strategy for synthesizing cyclohexanone oxime (CHO), an important feedstock in nylon-6 production, through the hydrogenative coupling of NO3− and cyclohexanone (CYC) using a rutile titanium dioxide (R-TiO2) catalyst under ambient conditions. The CHO productivity achieved 127.3 µmol cm−2 h−1 with a high Faradaic efficiency (FE) of 68.2% at a current density of 30 mA cm−2. Moreover, the yield of CHO reached 98.2%. We demonstrate that the electrosynthesis of CHO operates through a tandem reaction mechanism involving the in-situ generation of hydroxylamine (NH2OH) from NO3− reduction, followed by a spontaneous nucleophilic addition–elimination reaction between NH2OH and cyclohexanone. Additionally, we reveal that R-TiO2 exhibits a superior scaling relation with a high NH2OH generation rate and excellent cyclohexanone adsorption ability, which promotes CHO production. This electrochemical strategy is also effective for the synthesis of different oximes. Finally, we designed a coupling reaction system to realize the simultaneous production of CHO and CYC by combining cathodic NO3− reduction and anodic cyclohexane oxidation, demonstrating a greener and more economical approach. Download figure Download PowerPoint Previous articleNext article FiguresReferencesRelatedDetails Issue AssignmentNot Yet AssignedSupporting Information Copyright & Permissions© 2024 Chinese Chemical Society Downloaded 0 times PDF downloadLoading ...