Electrosynthesis of Nitriles from Nitrate and Aldehyde via C≡N Bond Construction
Cheng Xue, Shuaiqiang Jia, Jiapeng Jiao, Xiao Chen, Mengke Dong, Zhanghui Xia, Ting Deng, Hailian Cheng, Chunjun Chen, Haihong Wu, Mingyuan He, Buxing Han
Abstract
Electrocatalytic nitrate reduction offers a promising approach to synthesizing valuable organic nitrogen compounds via C–N coupling, serving as a pivotal solution to the pressing nitrate pollution issue. While significant progress has been made in electrosynthesizing C–N and C═N compounds, the electrosynthesis of nitriles with C≡N bond formation via NO x as nitrogen sources remains challenging. Herein, we introduce a novel method for efficient synthesizing nitriles through electrocatalytic coupling of nitrate ions (NO 3 – ) with aldehydes under ambient conditions, employing ZnO/Sn/SnO 2 as the electrocatalyst. In situ spectroscopic characterization and theoretical calculations demonstrated that the adsorption and accumulation of *NH 2 OH and *RCHO on the catalyst plays a central role in the efficient reaction. The key C–N bond-forming step is found to be the formation of hydroxylamine from nitrate reduction and its subsequent condensation with *RCHO. The C–N coupling strategy can be applied to the synthesis of fatty nitrile and (hetero)aromatic nitrile compounds. This study opens the way for nitriles electrosynthesis from nitrogen wastes, which could contribute to utilization of nitrogen resources.