Coordination Shell Dependent Activity of CuCo Diatomic Catalysts for Oxygen Reduction, Oxygen Evolution, and Hydrogen Evolution Reaction

Challenges in rational designing dual-atom catalysts (DACs) give a strong motivation to construct coordination-activity correlations. Here, thorough coordination-activity correlations of DACs based on how the changes in coordination shells (CSs) of dual-atom Cu,Co centers influence their electrocatalytic activity in oxygen reduction reaction(ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) is constructed. First, Cu,Co DACs with different CSs modifications are fabricated by using a controlled "precursors-preselection" approach. Three DACs with unique coordination environments are characterized as secondary S atoms that directly bond to Cu,Co-N6 in lower CSs, indirectly bond in neighboring CSs, and are doped in higher CSs, respectively. Then, experimentally and theoretically, a coordination correlation resembling a planet-satellite system, where satellite coordinated atoms (heteroatom N, S) surround Cu-Co dual-atom entity in various orbitals CSs. By evaluating electrocatalytic activity indicators, differences are identified in electronic structure and electrocatalytic performance of Cu and Co centers in ORR, OER, and HER. Interestingly, initial CSs modifications for DACs may not always be advantageous for electrocatalysis. This work offers valuable insight for designing DACs for diverse applications. Series of Cu,Co dual-atom catalysts (DACs) with different coordination environment are controllable synthesized, where secondary S atoms are incorporated in different coordination shells (CSs) of Cu,Co centers. It is found that CSs engineering directly result in electronic redistribution of Cu,Co centers, thus regulating the electrocatalytic performance in ORR/OER/HER. This work offers a guidance for the rational design of targeted DACs.image