Boosted N<sub>2</sub> Activation through 4f–2p–3d Orbital Hybridization for Efficient Nitrate Electrosynthesis
Shuyuan Li, Xiaoxuan Wang, Xinyue Chi, Yuanyuan Xiong, Yanfei Sun, Zheng Tang, Xueying Gao, Huiying Zhang, Jingxian Li, Kaiqi Nie, Jiangzhou Xie, Zhiyu Yang, Yi‐Ming Yan
Abstract
Abstract The electrochemical N 2 oxidation reaction (NOR) has emerged as a promising approach for achieving high selectivity in nitric acid (HNO 3 ) production. However, the sluggish N 2 activation process in NOR due to the high cleavage energy barrier of the N≡N bond remains a challenge. Herein, a novel orbital hybridization strategy for tuning the NOR performance through the construction of cerium (Ce) 4f–O 2p–Co 3d network in Ce‐doped Co 3 O 4 (Ce–Co 3 O 4 ) is proposed. The Ce–Co 3 O 4 catalyst exhibits an enhanced HNO 3 yield of 24.76 µg h −1 mg cat −1 and a promoted Faradaic efficiency of 31.93% in 0.1 m Na 2 SO 4 electrolyte under ambient conditions compared to those of the pure Co 3 O 4 (13.75 µg h −1 mg cat −1 and 23.43%). Density functional theory caculations demonstrate the strong 4f–2p–3d orbital hybridization and electron transfer in Ce–Co 3 O 4 . Moreover, a series of in situ techniques provide direct evidence of stronger adsorption peaks for Co─N bond and the key intermediate *NO formed after N 2 activation on the surface of Ce–Co 3 O 4 . This work provides a promising route for the preparation of efficient NOR catalysts and sheds light on the mechanism of N 2 activation through orbital hybridization.