Boosting Electrocatalytic Nitrate Reduction to Ammonia via Promoting Water Dissociation
Yiyang Zhou, Ruizhi Duan, Hao Li, Miao Zhao, Chunmei Ding, Can Li
Abstract
Electrocatalytic nitrate reduction reaction (NO 3 – RR) opens opportunities for ammonia production. The sluggish kinetics of this multielectron and multiproton process has been regarded as the key issue. Herein, we report a Cu 1 Co 5 alloy for electrocatalytic NO 3 – RR to NH 3 . It achieves a high current density (453 mA cm –2 ) and Faradaic efficiency (96.2%) for NH 3 production at 0.075 V vs RHE, with a half-cell energy efficiency of 44.9%, higher than those of Cu, Co, and other Co-based alloys, and is among the highest value reported. We found that the interaction between Cu and Co reorganizes their electronic structure in alloys. The NO 3 – adsorption switches to a spontaneous process, and the *NO → *N and *NH → *NH 2 processes are promoted. Importantly, the water dissociation process concerted with the transformation of N-species is proven to be rate-determining, which is facilitated on Co sites in the Cu 1 Co 5 alloy and is essential for the enhanced NO 3 – RR. This inspires us a strategy for designing more efficient catalysts for NO 3 – RR under alkaline condition by promoting the H 2 O dissociation process.