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 Systems for NOx Valorization in Organonitrogen Synthesis

“…Through DFT calcula-tions and in situ characterizations, the ability of Fe to accumulate adsorbed NH 2 OH and cyclohexanone was proved to be response for the high efficiency (Figure 6c). [54] Similarly, Li group [55] designed a catalyst (AlÀ NFM) with AlÀ O/N unsaturated coordination sites, synthesizing pyridine oximes by coupling electrochemistry with pyridine aldehydes, and pralidoxime iodide (an efficient antidote for organophosphorus poisoning) was further synthesized by a simple nucleophilic addition reaction. Through this method, other 5 kinds of pyridine oximes and additional 14 kinds of oximes featuring diverse functional groups, are successful synthesized (Figure 6d).…”

Electrocatalytic Systems for NOx Valorization in Organonitrogen Synthesis

“…Through DFT calcula-tions and in situ characterizations, the ability of Fe to accumulate adsorbed NH 2 OH and cyclohexanone was proved to be response for the high efficiency (Figure 6c). [54] Similarly, Li group [55] designed a catalyst (AlÀ NFM) with AlÀ O/N unsaturated coordination sites, synthesizing pyridine oximes by coupling electrochemistry with pyridine aldehydes, and pralidoxime iodide (an efficient antidote for organophosphorus poisoning) was further synthesized by a simple nucleophilic addition reaction. Through this method, other 5 kinds of pyridine oximes and additional 14 kinds of oximes featuring diverse functional groups, are successful synthesized (Figure 6d).…”

“… (a) Oxime production in the electro‐synthesizing leucine process using CoFe‐SSM at various potentials, [30] Copyright 2023, Wiley‐VCH GmbH; (b) the schematic diagram of a pathway for NO and cyclohexanone to produce CHO, [54] Copyright 2023, Wiley‐VCH GmbH; (c) Experimental amplification for the electrocatalytic synthesis of cyclohexanone oxime toward caprolactam production, [54] Copyright 2023, Wiley‐VCH GmbH; (d) the FE of various as synthesized pyridine oximes over Al‐NFM with Al−O/N unsaturated coordination sites from pyridine aldehyde [55] . Copyright 2023, Wiley‐VCH GmbH; (e) Yield and selectivity of different substrates over Cu−S electrocatalyst [56] .…”

Integration of plasma and electrocatalysis to synthesize cyclohexanone oxime under ambient conditions using air as a nitrogen source

“…Therefore, the above results present the possible reaction pathways of NO 3 − to NH 2 OH intermediates through The high selectivity of >99.9% is an obvious advantage of cyclohexanone oxime production through an electrocatalysis strategy. 8,35,36 Interestingly, the reduction of cyclohexanone and cyclohexanone oxime were not detected as side reactions because no GC-MS peaks of cyclohexanol or cyclohexylamine appeared in Fig. S6A.…”