Advances in ambient selective electrohydrogenation of nitrogen to ammonia: strategies to strengthen nitrogen chemisorption

Abstract

Electrochemical synthesis of ammonia from stable dinitrogen molecules has attracted substantial research interest recently. However, N₂ reduction reaction (NRR) over an electrocatalyst is hampered by the chemical inertness of the N₂ molecule and strong competition from the hydrogen evolution reaction, rendering limited selectivity and faradaic efficiency of existing catalysts. The bottleneck of the catalyst design exists in the rational synthesis of catalytic centers with efficient N₂ chemisorption and subsequent activation. To date, various strategies have been proposed and utilized to improve the chemisorption capability of catalysts toward N₂. Herein, a timely and comprehensive review of emerging strategies to strengthen N₂ chemisorption for efficient NH₃ electrosynthesis is presented. The critical challenges that prevent the application of the NRR technique are analyzed initially. Subsequently, various strategies for enhancing the chemisorption ability of electrocatalysts toward nitrogen molecules are comprehensively summarized, containing defect engineering, crystallographic tailoring, and hybrid engineering. Finally, perspectives on stimulating the practical application of NRR technology are provided.