Core–<b>S</b>hell Engineering Boosted Active Hydrogen Generation in Cu<sub>2</sub><b><sub>–</sub><sub><i>x</i></sub></b>S/MoS<sub><b>2</b></sub> Quantum Dots for Efficient Electrocatalytic Nitrate Reduction to Ammonia
Tianyao Jiang, Yanhong Liu, Dongxu Zhang, Qitao Chen, Lixia Li, Naiyun Liu, Chunxing Zhou, Longhua Li, Baodong Mao
Abstract
The electrochemical nitrate reduction reaction (NO 3 RR) emerges as a promising method for ammonia (NH 3 ) production, which faces the dilemma of inhibiting the hydrogen evolution reaction (HER) and promoting active hydrogen (H ads ) supply for hydrogenation of nitrogen intermediates. Here, a core–shell structure engineering strategy is developed for Cu 2– x S/MoS 2, where the strong H ads adsorption and storage capacity can accelerate the hydrogenation of nitrogen intermediates. As a result, an eminent NH 3 yield of 0.178 mmol h –1 cm –2 and a Faradaic efficiency of 84.5% were achieved. A series of electrochemical tests demonstrate that the tuning of the Cu 2– x S/MoS 2 interface can improve the electrochemical activity and the conversion of NO 2 –, while avoiding the strong HER that can effectively retain the H ads . The density functional theory calculation further demonstrates that the Cu 2– x S/MoS 2 interface has a strong *H retention and adsorption ability to promote the NO 3 RR process. This work offers a novel perspective on the manipulation of H ads generation for the NO 3 RR.