Electronic structure and geometric construction modulation of carbon-based single/dual atom catalysts for electrocatalysis

Both carbon-based single atom catalysts (SACs) and dual atom catalysts (DACs) have garnered significant attention in the field of electrochemical reactions because of the impressive attributes, including exceptional catalytic activity, selectivity, and cost-effectiveness. The ability to modulate the electronic structure and geometric construction of active sites within SACs/DACs is paramount for unleashing their complete potential, which in turn can ultimately dictate catalytic behavior with unprecedented precision. In this review, the recent major developments of the regulation strategies for modulating electronic structure and geometric construction of carbon-based SACs/DACs are summarized. For the SACs, the recently reported modulation methods are categorized into four strategies, including adjusting the density of single atoms, defect engineering, confinement effect and strain engineering. And for the DACs, the five methods contain bonded dual-atom adjustment, non-bonded and bridged dual-atom adjustment, metal and nonmetal dual-atom adjustment, bilayer dual-atom adjustment and homogeneous dual-atom adjustment. The recently developed synthetic strategies are comprehensively summarized, especially their electronic structure and geometric configuration are discussed in detail, the different catalytic applications of electrochemical reactions, and their unique catalytic mechanism are highlighted. Finally, the challenges and prospects of SACs/DACs for tailoring their electronic structures and geometric arrangements are further discussed.