Selective electroreduction of nitrate to ammonia with high Faradaic efficiency on nanocrystalline silver
Zhengyang Liu, Changhong Wang, Chongjun Chen, Chang Ming Li, Chunxian Guo
Abstract
Electrocatalytic reduction of nitrate to ammonia is a promising approach to both green synthesis of ammonia and nitrate pollution disposal. However, current cathode catalysts display relatively low selectivity and Faradaic efficiency. We demonstrate here that nanocrystalline silver (nano-Ag) can achieve both high selectivity and high Faradaic efficiency. Nano-Ag at −0.33 V vs. RHE delivers a current density of −194.31 mA cm−2, exhibits a Faradaic efficiency of up to 96.4% and has selectivity of 89.6%. It also exhibits good stability, retaining 91.1% of the original selectivity and about 100% of the original Faradaic efficiency after 4 cycles, suggesting that nano-Ag is a highly efficient catalyst for reduction of nitrate to ammonia.