Efficient Nitrogen Fixation to Ammonia through Integration of Plasma Oxidation with Electrocatalytic Reduction
Laiquan Li, Cheng Tang, Xiaoyang Cui, Yao Zheng, Xuesi Wang, Haolan Xu, Shuai Zhang, Tao Shao, Kenneth Davey, Shi‐Zhang Qiao
Abstract
Abstract Present one‐step N 2 fixation is impeded by tough activation of the N≡N bond and low selectivity to NH 3 . Here we report fixation of N 2 ‐to‐NH 3 can be decoupled to a two‐step process with one problem effectively solved in each step, including: 1) facile activation of N 2 to NO x − by a non‐thermal plasma technique, and 2) highly selective conversion of NO x − to NH 3 by electrocatalytic reduction. Importantly, this process uses air and water as low‐cost raw materials for scalable ammonia production under ambient conditions. For NO x − reduction to NH 3 , we present a surface boron‐rich core–shell nickel boride electrocatalyst. The surface boron‐rich feature is the key to boosting activity, selectivity, and stability via enhanced NO x − adsorption, and suppression of hydrogen evolution and surface Ni oxidation. A significant ammonia production of 198.3 μmol cm −2 h −1 was achieved, together with nearly 100 % Faradaic efficiency.