Hollow Square Ni-Doped Copper Oxide Catalyst Boosting Electrocatalytic Nitrate Reduction
Yi Li, Yi Li, Jinshan Wei, Hexing Lin, Ying Guo, Xihui Lu, Shaoqing Liu, Hongze Liu, Mengyao Tang, Ji Zhou, Yayun Li, Yayun Li
Abstract
The electrochemical nitrate reduction reaction to ammonia (NRA) is gaining increasing attention as an eco-friendly approach to convert harmful nitrate pollutants into high-value product ammonia. NRA involves two critical rate-determining steps: hydrogenation of the *NO and *NOH intermediates. The composite of Ni and Cu has been demonstrated to exhibit synergistic catalytic effects; however, research on the combination of Ni and CuO remains limited. Herein, an advanced Ni-doped copper oxide catalyst with a hollow square morphology (Ni–CuO) is reported with a Faradaic efficiency of 95.26% at −0.8 V vs RHE and a high yield rate of 0.94 mmol h –1 cm –2, demonstrating high selectivity and stability. Complementary analyses demonstrated that the active hydrogen generated at the Ni sites facilitates the hydrogenation of *NO x adsorbed on Cu sites. Theoretical computations further confirm the thermodynamic viability of this bimetallic catalytic mechanism. Furthermore, an Al–NO 3 – battery with a high open-circuit voltage was constructed by using Ni–CuO as the cathode. This work presents a synergistically modulated catalyst for complex catalytic processes and introduces a highly efficient Al–NO 3 – battery capable of simultaneous NH 3 synthesis and electrical energy conversion, underscoring its potential in efficient catalysis and the development of the energy and chemical industries.