O-Induced Diatomic Fe–Mo Mimetic Enzyme for Efficient Electrocatalytic Nitrogen Reduction at Universal pH
Yuanyuan Yu, Qingtong Zhang, Simin Wei, Guangfu Qian, Qian He, Wenyan Yin, Douyong Min, Shuangfei Wang, Yuliang Zhao
Abstract
Electrochemical nitrogen reduction reaction (ENRR) provides a sustainable route for the NH 3 synthesis. However, designing catalysts that facilitate efficient electron/proton transfer and the hydrogenation of multiple intermediates remains a challenge. In this study, inspired by the natural nitrogenase proteins, a biomimetic Fe–Mo diatomic catalyst (FeMo-CDW(CT-3h)) was designed for efficient ENRR. The microenvironment of Fe–Mo diatomic sites was precisely tuned using the O-induced atomic confinement effect, where O atoms modulate the activity of the sites. FeMo-CDW(CT-3h) with four O atoms achieves a record-breaking NH 3 yield at universal pH as well as high stability (250 h and 10 cycles) due to its optimal electron transfer efficiency. In particular, the NH 3 yield of 336.03 μg h –1 cm –2 in 0.1 M HCl was over three times higher than the previously reported maximum. Theoretical calculations reveal that the hybridization of Fe–Mo d orbitals with N 2 * antibonding orbitals enhances electron transfer, extends and weakens the N≡N bond, and accelerates proton transfer and hydrogenation, thereby increasing NH* antibonding orbitals enhances electron transfer, extends and weakens the N≡N bond, and accelerates proton transfer and hydrogenation, thereby increasing NH 3 generation.