Atomic-Site Coordination Tuning for Precise CO 2 Electroconversion

Electrochemical carbon dioxide reduction (ECR) presents a promising avenue for achieving carbon neutrality by converting greenhouse gases into high-value fuels and chemicals. However, the advancement of ECR hinges on the precise design and synthesis of catalysts that exhibit high activity, selectivity, and stability. Single-atom site catalysts (SASCs), benefiting from their maximum atom-utilization efficiency, uniform and tunable active sites, and unique electronic properties arising from strong metal-support interactions, have emerged as a powerful platform for investigating the structure-activity relationship of ECR. By tuning coordination environments (e.g., coordination types and numbers) of isolated metal atoms, the electronic structure of metal active sites can be precisely modified for governing the selective synthesis of ECR products. Herein, this review systematically summarizes the precise synthesis strategies, advanced characterization techniques, and structure-activity relationships of SASCs in various coordination environments. Furthermore, the limitations and necessary precautions associated with the current characterization techniques are also discussed. Finally, we outline the future challenges and potential research directions of SASCs in the field of ECR.