Current Progress of Electrocatalysts for Ammonia Synthesis Through Electrochemical Nitrogen Reduction Under Ambient Conditions

Ammonia, one of the most important chemicals and carbon-free energy carriers, is mainly produced by the traditional Haber-Bosch process operated at high pressure and temperature, which results in massive energy consumption and CO(2)emissions. Alternatively, the electrocatalytic nitrogen reduction reaction to synthesize NH(3)under ambient conditions using renewable energy has recently attracted significant attention. However, the competing hydrogen evolution reaction (HER) significantly reduces the faradaic efficiency and NH(3)production rate. The design of high-performance electrocatalysts with the suppression of the HER for N(2)reduction to NH(3)under ambient conditions is a crucial consideration for the development of electrocatalytic NH(3)synthesis with high FE and NH(3)production rate. Five kinds of recently developed electrocatalysts classified by their chemical compositions are summarized, with particular emphasis on the relationship between their optimal electrocatalytic conditions and NH(3)production performance. Conclusions and perspectives are provided for the future design of high-performance electrocatalysts for electrocatalytic NH(3)production. The Review can give practical guidance for the design of effective electrocatalysts with high FE and NH(3)production rates.