Recent Advances in the Application of Structural-Phase Engineering Strategies in Electrochemical Nitrogen Reduction Reaction

Ammonia (NH3) exists as an important chemical raw material in the chemical industry and national economy of all countries in the world. The widely used Haber-Bosch ammonia synthesis process not only requires a large amount of highly purified hydrogen, but also is inseparable from high-temperature and high-pressure reaction conditions, resulting in numerous problems that cannot be fundamentally solved in terms of safety, efficiency, cost, etc. It is considered to be an alternative technology with great potential to achieve the synthesis of ammonia under normal temperature and pressure making use of electrochemical nitrogen reduction reaction (NRR), which utilizes water in aqueous solution systems in replacement of hydrogen as hydrogen source. This paper succinctly explains the basic mechanism for electrocatalytic ammonia synthesis from the reduction of nitrogen in aqueous solution systems. Based on the research progress in the past year, the principles and related researches of constructing electrocatalysts of NRR using five structural-phase strategies including defect engineering, interface engineering, strain engineering, atomic ordering engineering, and single-atom engineering are reviewed. Finally, this paper provides an outlook to the future research and application.