Nanomaterials (Basel). 2023 Jan 11;13(2):309. doi: 10.3390/nano13020309.
Single-atom catalysts (SACs) have emerged as well-known catalysts in renewable energy storage and conversion systems. Several supports have been developed for stabilizing single-atom catalytic sites, e.g., organic-, metal-, and carbonaceous matrices. Noticeably, the metal species and their local atomic coordination environments have a strong influence on the electrocatalytic capabilities of metal atom active centers. In particular, asymmetric atom electrocatalysts exhibit unique properties and an unexpected carbon dioxide reduction reaction (CO2RR) performance different from those of traditional metal-N4 sites. This review summarizes the recent development of asymmetric atom sites for the CO2RR with emphasis on the coordination structure regulation strategies and their effects on CO2RR performance. Ultimately, several scientific possibilities are proffered with the aim of further expanding and deepening the advancement of asymmetric atom electrocatalysts for the CO2RR.