The nitrogen electroreduction reaction (NRR) in aqueous solutions at ambient conditions represents an attractive prospect to produce ammonia, but the development of long-term stable and low-cost catalysts with high-efficiency and high-selectivity remains a great challenge. Single-atom catalysts have emerged as a new frontier in heterogeneous catalysis, and demonstrated distinguishing performances for various reactions due to their high catalytic activity with a significantly reduced amount of metals used. The emerging metal-free catalysts for NRR have attracted increasing attention due to their intrinsic advantages, such as low cost, high reliability, good biocompatibility, and excellent sustainability

In this talk, we will present our recent efforts in designing single-atom and metal-free electrocatalysts to realize nitrogen reduction reaction (NRR) at ambient conditions. Besidesidentifying promising catalysts for N₂fixation, we will emphasize the designing principles and the procedure in screening effective NRR catalysts based on the mechanism understanding.