Recent Advances in Noble‐Metal‐Free Catalysts for Electrocatalytic Synthesis of Ammonia under Ambient Conditions

Abstract Ammonia is an essential chemical for producing fertilizers and energy carriers. However, the industrial Haber–Bosch process causes huge CO 2 emissions and energy waste. As a promising alternative for Haber‐Bosch process, electrochemical synthesis of ammonia has drawn much attention. Catalysts, as a vital part of electrochemical nitrogen reduction reaction (NRR), have developed rapidly in recent years. Compared to noble‐metal catalysts, noble‐metal‐free catalysts possess a low‐cost advantage. In this review, noble‐metal‐free catalysts, including metal‐based materials, metal organic frameworks (MOFs), MXenes, and metal‐free materials, are summarized. In addition, effective design strategies are discussed, along with the main problems and some potential directions of noble‐metal‐free NRR catalysts.