Interface coupling of Ni2P@Cu3P catalyst to facilitate highly-efficient electrochemical reduction of nitrate to ammonia

Abstract

Electrochemical reduction of nitrate pollutants to ammonia is quite attractive in the context of the energy crisis and sustainable development, and developing efficient electrocatalysts with high NH3 yield rate and FE is particularly important and imminent. Herein, an efficient catalyst, Ni2P@Cu3P, for electrochemical reduction of nitrate to ammonia (NRA) was successfully constructed in situ on a copper foam. The interface coupling in Ni2P@Cu3P significantly optimized its surface electronic structure and induced the exposure of more metal-P bonds on the catalyst surface, resulting in its brilliant NRA performance with NH3 FE of 96.97 %, yield rate of 0.2784 mmol·h−1·cm−2, selectivity rate of 98.07 % and NO3− conversion rate of 99.35 %. DFT theoretical calculations indicated that optimization of the catalyst surface electronic structure by interface electron coupling significantly regulated the adsorption intensities of NRA intermediates on the catalyst surface, improving the catalytic performance of the NRA. The present work has some reference significance for understanding the design principle of efficient electrocatalysts for the reduction of nitrate to ammonia.