Surface Coordination Chemistry of Atomically Dispersed Metal Catalysts

Atomically dispersed metal catalysts (ADCs), as an emerging class of heterogeneous catalysts, have been widely investigated during the past two decades. The atomic dispersion nature of the catalytic metal centers makes them an ideal system for bridging homogeneous and heterogeneous metal catalysts. The recent rapid development of new synthetic strategies has led to the explosive growth of ADCs with a wide spectrum of metal atoms dispersed on supports of different chemical compositions and natures. The availability of diverse ADCs creates a powerful materials platform for investigating mechanisms of complicated heterogeneous catalysis at the atomic levels. Considering most dispersed metal atoms on ADCs are coordinated by the donors from supports, this review will demonstrate how the surface coordination chemistry plays an important role in determining the catalytic performance of ADCs. This review will start from the link between coordination chemistry and heterogeneous catalysis. After the brief description on the advantages and limitations of common structure characterization methods in determining the coordination structure of ADCs, the surface coordination chemistry of ADCs on different types of supports will be discussed. We will mainly illustrate how the local and vicinal coordination species on different support systems act together with the dispersed catalytic metal center to determine the catalytic activity, selectivity, and stability of ADCs. The dynamic coordination structure change of ADCs in catalysis will be highlighted. At the end of the review, personal perspectives on the further development of the field of ADCs will be provided.