Computational Screening of High Activity and Selectivity TM/g-C<sub>3</sub>N<sub>4</sub> Single-Atom Catalysts for Electrocatalytic Reduction of Nitrates to Ammonia
Lingling Lv, Yanqing Shen, Jiajia Liu, Xianghui Meng, Xu Gao, Min Zhou, Yu Zhang, Dewei Gong, Yangdong Zheng, Zhongxiang Zhou
Abstract
Electrocatalytic reduction of nitrates (NO3RR) selectively generating ammonia (NH3) opens up a new idea for treating nitrates in wastewater, which not only reduces nitrates but also obtains the valuable product ammonia. By first-principles calculations, we explore the activity and selectivity for NO3RR to NH3 of TM/g-C3N4 single-atom catalysts. Six TM/g-C3N4 catalysts (TM = Ti, Os, Ru, Cr, Mn, and Pt) are selected by a four-step screening method. Ru/g-C3N4 is the most promising of these six TM/g-C3N4 catalysts because of its lowest energy barrier and extraordinary selectivity. The origin of the NO3RR activity of Ru/g-C3N4 is explained from the viewpoint of NO3– adsorption. In addition, the hydrogen evolution reaction has also been implied to be uncompetitive for the poor adsorption on H atoms. This work provides a screening mechanism for finding new catalysts for NO3RR to NH3, promotes the development of NO3RR, and provides a stimulating impetus for further experimental exploration.