Electroreduction of Nitrate to Ammonia on Palladium–Cobalt–Oxygen Nanowire Arrays
Min Liu, Qiqi Mao, Keke Shi, Ziqiang Wang, You Xu, Xiao‐Nian Li, Liang Wang, Hongjing Wang
Abstract
Developing high-efficiency electrocatalysts for the selective reduction of nitrate to valuable ammonia is of great significance. Herein, Pd–PdO-modified Co3O4 nanowire arrays on nickel foam (PdCoO/NF) are fabricated by a facile cation-exchange reaction. Pd and PdO can facilitate the generation of adsorbed hydrogen, and abundant oxygen vacancies can promote nitrate activation. Therefore, the PdCoO/NF exhibits a superior nitrate conversion rate (89.3%), Faradaic efficiency (88.6%), and ammonium selectivity (95.3%) at −1.3 V versus a saturated calomel electrode. The source of the produced ammonia is confirmed by 15N isotope labeling experiments and 1H magnetic resonance. This presented synthetic method provides a powerful strategy for the preparation of nanowire arrays with controllable compositions for selective nitrate electroreduction to ammonia.