Dynamically Restructuring Nanoporous Cu–Co Electrocatalyst for Efficient Nitrate Electroreduction to Ammonia
Xue Zhou, Wence Xu, Yanqin Liang, Hui Jiang, Zhaoyang Li, Shuilin Wu, Zhonghui Gao, Zhenduo Cui, Shengli Zhu
Abstract
The electrochemical nitrate (NO 3 – ) reduction reaction (NITRR) to ammonia (NH 3 ) offers an environmentally friendly alternative for NH 3 synthesis but suffers from limited NH 3 yield and low Faradaic efficiency (FE) due to the sluggish kinetics of the hydrogenation process. Herein, nanoporous Cu/CoOOH heterostructure is reported as an efficient electrocatalyst for NITRR. The catalyst achieves a high NH 3 yield rate of 275.9 μmol h –1 cm –2 (689.8 mmol h –1 g cat –1 ) and 836.8 μmol h –1 cm –2 (2092.0 mmol h –1 g cat –1 ), with corresponding FE values of 85.3 and 91.5% in 200 and 1400 ppm of NO 3 – -N electrolyte, respectively. In situ Raman spectra reveal that the Cu/CoOOH heterostructure is derived from synergistic chemical/electrochemical redox reaction between NO 3 – and the CuCo alloy during the NITRR process. Theoretical simulations indicate that Cu/CoOOH exhibits enhanced *NO 2 affinity and reduces the energy barrier in the rate-determining *NO 2 H formation step, effectively facilitating NO 3 – reduction to NH 3 .