Atomically Dispersed Cu Sites on Dual‐Mesoporous N‐Doped Carbon for Efficient Ammonia Electrosynthesis from Nitrate
Mengqiu Xu, Qifan Xie, Delong Duan, Ye Zhang, Yuhu Zhou, Haiqiao Zhou, Xiaoyu Li, Yao Wang, Peng Gao, Wei Ye
Abstract
Abstract The industrial Haber‐Bosch process for ammonia synthesis is extremely important in modern society. However, it is energy intensive and leads to severe pollution, which has motivated eco‐friendly NH 3 synthesis research. Electroreduction of contaminant nitrate ions back to NH 3 is an effective complement but is still limited by low NH 3 yields and nitrate‐to‐NH 3 selectivities. In this study, the electrochemical nitrate reduction reaction (NTRR) is carried out over a single‐atom Cu catalyst. Atomically dispersed Cu sites anchored on dual‐mesoporous N‐doped carbon framework display excellent NTRR performance with NH 3 production rate of 13.8 mol g cat −1 h −1 and NO 3 − ‐to‐NH 3 faradaic efficiency (FE) of 95.5 % at −1.0 V. Cu−N−C catalyst can sustain continuous 120 h NTRR test in the simulated NH 3 synthesis scenarios with large current density (about 200 mA cm −2 ) and amplified volume of NO 3 − solution (9 times). Theoretical calculations reveal that atomically dispersed Cu 1 −N 4 sites reduce the energy barrier of potential‐determining step in NTRR and promote the decomposition of primary intermediate in NO 3 − ‐to‐N 2 process. These findings provide a guideline for the rational design of highly active, selective and durable electrocatalysts for the NTRR.