Theoretical Screening of Efficient TM/GaN Single-Atom Catalysts for Electroreduction of Nitrate to Ammonia
Huifang Ma, Saifei Yuan, Shujuan Li, Jiayao Wang, Huiyun Zhang, Yuping Zhang, Juqian Yang, Jinbo Sun, Ke Xu, Shulai Lei
Abstract
The electrocatalytic nitrate (NO 3 – ) reduction reaction (NO 3 RR) represents a promising strategy for synthesizing ammonia (NH 3 ) under milder conditions, providing an environmentally friendly alternative to the Haber–Bosch process. However, current electrochemical NO 3 RR catalysts are limited in terms of selectivity and catalyst stability. Herein, novel efficient single-atom catalysts for selective and active electrochemical reduction of nitrate to ammonia, based on transition metals doped on a gallium nitride (GaN) monolayer, are investigated by using density functional theory calculations. Among 18 candidates, V/GaN and Ru/GaN are identified as the most effective catalysts, demonstrating low limiting potentials of –0.39 V and –0.46 V, respectively. Ab initio molecular dynamics simulations further confirm the kinetic stability of these catalysts, with the structures of V/GaN and Ru/GaN remaining stable after 5 ps at 500 K. Our findings suggest that V/GaN and Ru/GaN are promising electrocatalysts for efficient and selective NO 3 RR to NH 3, warranting further experimental validation.