Electrocatalytic Synthesis of Nylon‐6 Precursor at Almost 100 % Yield

Abstract

AbstractSynthesis of cyclohexanone oxime via the cyclohexanone‐hydroxylamine process is widespread in the caprolactam industry, which is an upstream industry for nylon‐6 production. However, there are two shortcomings in this process, harsh reaction conditions and the potential danger posed by explosive hydroxylamine. In this study, we presented a direct electrosynthesis of cyclohexanone oxime using nitrogen oxides and cyclohexanone, which eliminated the usage of hydroxylamine and demonstrated a green production of caprolactam. With the Fe electrocatalysts, a production rate of 55.9 g h−1 gcat−1 can be achieved in a flow cell with almost 100 % yield of cyclohexanone oxime. The high efficiency was attributed to their ability of accumulating adsorbed hydroxylamine and cyclohexanone. This study provides a theoretical basis for electrocatalyst design for C−N coupling reactions and illuminates the tantalizing possibility to upgrade the caprolactam industry towards safety and sustainability.