Formation of Interfacial Cu‐[O<i><sub>X</sub></i>]‐Ce Structures with Oxygen Vacancies for Enhanced Electrocatalytic Nitrogen Reduction
Peng Jing, Peixin Liu, Minghao Hu, Xuan Xu, Baocang Liu, Jun Zhang
Abstract
Abstract Electrochemical nitrogen reduction powered by renewable electricity is a promising strategy to produce ammonia. However, the lack of efficient yet cheap electrocatalysts remains the biggest challenge. Herein, hybrid Cu 2 O‐CeO 2 ‐C nanorods are prepared on copper mesh through a metal‐organic framework template route. The Cu‐loaded Ce‐MOF is thermally converted to Cu 2 O‐CeO 2 heterojunctions with interfacial Cu‐[O X ]‐Ce structures embedded in carbon. Theoretical calculations reveal the lower formation energy of oxygen vacancies in Cu‐[O X ]‐Ce structures than in the Cu 2 O or CeO 2 phase. The Cu‐[O X ]‐Ce structures with oxygen vacancies enable the formation of interfacial electron‐rich Cu(I) species which show significantly enhanced performance toward electrocatalytic nitrogen reduction with an NH 3 yield of 6.37 × 10 −3 µg s −1 cm −2 and a Faradaic efficiency of 18.21% in 0.10 m KOH at −0.3 V versus reversible hydrogen electrode. This work highlights the importance of modulation of charge distribution of Cu‐based electrocatalysts to boost the activity toward nitrogen reduction.