Asymmetric diatomic electrocatalysts: Design, synthesis and applications

Asymmetric diatomic catalysts (ADCs) represent a promising class of sustainable electrocatalysts, featuring exceptional atom efficiency and dual active sites with asymmetric coordination environments. The asymmetric charge distribution in ADCs generates a local built-in electric field, enhancing charge separation/transfer and facilitating synergistic multi-step catalysis. This inherent structural complexity boosts catalytic performance by modulating the adsorption orientation and electronic configuration of intermediates. Importantly, the establishment of precise structure-activity correlations and the elucidation of underlying reaction mechanisms are of critical significance. This review provides a comprehensive overview of recent advancements in ADCs, with particular emphasis on classification methodologies, the application of artificial intelligence (AI), advanced characterization techniques, and their applications in key electrocatalytic reactions, such as oxygen reduction (ORR), oxygen evolution (OER), hydrogen evolution (HER), and carbon dioxide reduction (CO₂RR). Finally, the unresolved challenges and proposes potential research directions to advance the implementation of ADCs in energy systems are discussed.