Transition Metal‐Nitrogen‐Carbon Single‐Atom Catalysts Enhanced CO2 Electroreduction Reaction: A Review

Abstract As the global energy crisis and environmental challenges worsen, CO 2 conversion has emerged as a focal point in international research. CO 2 electroreduction reaction (CO 2 ER) is a green and sustainable technology that converts CO 2 into high‐value chemicals, thereby achieving the recycling of carbon resources. However, the activity and selectivity are constrained by the performance of the catalyst. Although traditional N‐doped carbon‐based catalysts exhibit excellent performance toward CO 2 ER, the atomic utilization rate in these materials is far from 100 %. Single atom catalysts (SACs) can attain nearly 100 % atomic utilization efficiency because of the fully exposing metal atoms. Therefore, SACs have emerged as one of the hot research materials in the field of CO 2 ER. Recently, transition metal‐nitrogen‐carbon single‐atom catalysts (TM−N−C SACs) have flourished because of their extraordinary catalytic activity, low cost, and excellent stability, demonstrating enormous application prospects in CO 2 ER. In this review, we concentrate on TM−N−C SACs that electrochemically reduce CO 2 to high value products. A comprehensive and detailed discussion were conducted on the synthesis method, chemical structure, chemical characterization of TM−N−C SACs, as well as their catalytic performance, active sources, and mechanism exploration for CO 2 ER. Finally, challenges and prospects for commercial application of TM−N−C SACs catalysts suitable for CO 2 ER are proposed.