Dual-atom catalysts: controllable synthesis and electrocatalytic applications

Electrocatalysis, as the nexus for energy storage and environmental remediation, requires developing low-cost and high-performing heterogeneous catalysts. Compared with the single atom catalysts (SACs), dual-atom catalysts (DACs) are attracting ever-increasing interest due to their higher metal loading, more versatile active sites and unique reactivity. However, controlled synthesis of DACs remains a great challenge, and their electrocatalytic applications are still in infancy. This review first discusses the synthesis of DACs by highlighting several synthetic strategies. Subsequently, we exemplify the unique reactivities of DACs in electrocatalytic applications including water splitting, oxygen reduction, carbon dioxide reduction and nitrogen reduction. The structure-activity relations of DACs are specifically discussed in comparison with that of SACs, on the basis of experimental and theoretical studies. Finally, the opportunities and challenges of DACs are summarized in terms of rational design, controlled synthesis, characterization, and applications.