Improving electrochemical nitrate reduction activity of layered perovskite oxide La2CuO4 via B-site doping

Electrochemical reduction of nitrate into ammonia (NO 3 - RR) has attracted great attentions because of the potential application for environmental remediation and energy storage. Despite many pioneering works on electrocatalysts development, the correlation between material properties and NO 3 - RR activity is still not fully understood. Herein, taking layered Ruddlesden-Popper type oxide La 2 CuO 4 as a model system, we demonstrate B-site cation doping as an effective approach for modulating NO 3 - RR activities. While Co dopant at Cu site strongly enhanced the NO 3 - RR activity and NH 3 selectivity, Zn and Ni dopants lead to slightly enhanced and suppressed NO 3 - RR performance, respectively. The distinct reaction kinetics of NO 3 - RR on La 2 Cu 0.8 M 0.2 O 4 with different dopants are further revealed by in-situ Fourier transform infrared spectroscopy measurement. Synchrotron-based X-ray absorption spectroscopy showed that B-site doping can effectively regulate metal-oxygen hybridization, leading to strongly tuned surface adsorption characteristics and NO 3 - RR activity. The results of this work can guide the design of highly active (electro)catalysts for environmental and energy devices.