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

Abstract

Synthesis 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 À 1 g cat À 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 CÀ N coupling reactions and illuminates the tantalizing possibility to upgrade the caprolactam industry towards safety and sustainability.

Electrocatalytic Coupling of Nitrate and Formaldehyde for Hexamethylenetetramine Synthesis via C–N Bond Construction and Ring Formation

“…7 Furthermore, our group presented a method for the synthesis of cyclohexanone oxime synthesis using Fe-based electrocatalysts. 8 With the aid of a flow cell, a production rate of 55.9 g h −1 g cat −1…”

“…Zhang’s team achieved the electrosynthesis of cyclohexanone oxime, a precursor to nylon-6, with a yield of 92%, an FE of 26%, and a selectivity of 99% . Furthermore, our group presented a method for the synthesis of cyclohexanone oxime synthesis using Fe-based electrocatalysts . With the aid of a flow cell, a production rate of 55.9 g h –1 g cat –1 , nearly 100% yield, and ∼20% FE were achieved.…”