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

Electrochemical reduction of nitrate into ammonia (NO3RR) 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 NO3RR activity is still not fully understood. Herein, taking layered Ruddlesden-Popper type oxide La2CuO4 as a model system, we demonstrate B-site cation doping as an effective approach for modulating NO3RR activities. While Co dopant at Cu site strongly enhanced the NO3RR activity and NH3 selectivity, Zn and Ni dopants lead to slightly enhanced and suppressed NO3RR performance, respectively. The distinct reaction kinetics of NO3RR on La2Cu0.8M0.2O4 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 NO3RR activity. The results of this work can guide the design of highly active (electro)catalysts for environmental and energy devices.

Automated summary

This study investigates the electrochemical reduction of nitrate into ammonia (NO3RR) using layered Ruddlesden-Popper type oxide La2CuO4 as a model system. B-site cation doping is shown to be an effective approach for modulating NO3RR activity, with different dopants leading to different performance. The results suggest that B-site doping can regulate metal-oxygen hybridization, leading to tuned surface adsorption characteristics and NO3RR activity.