Recent advances in single- and dual-atom catalysts for efficient nitrogen electro-reduction and their perspectives

Electrochemical nitrogen reduction reaction (ENRR) is emerging as a favorable option to the power-intensive Haber-Bosch process for ammonia synthesis. However, obstacles such as poor selectivity, low production rates, and competition against the hydrogen evolution reaction hinder its practical implementation. To address these, the design of highly active catalysts is critical. Single-atom catalysts (SACs) have shown great potential because of their maximized atom utilization, but their limited stability and low metal loading restrict their performances. On the other hand, dual-atom catalysts (DACs) are atomic catalysts with two metal atoms nearby and offer enhanced electrocatalytic performances by aligning with the N ​≡ ​N bond to enhance N₂ reduction efficiency, potentially overcoming the limitations of SAC. This review discusses recent advances in SACs and more importantly DACs for ENRR, highlighting their advantages, limitations, and the need for advanced characterization techniques to better understand catalyst behavior. The review concludes by underscoring the importance of research to optimize these catalysts for efficient and sustainable nitrogen fixation.