Fabrication of Single-Atom Catalysts with Precise Structure and High Metal Loading.

In recent years, single-atom catalysts (SACs) have attracted particular interest and have been demonstrated to be a promising material in energy conversion and chemical transformation due to their optimal atom utilization and unique size quantum effect. The development of a versatile and simple synthetic approach for SACs is important for further investigation of their properties. In this regard, several physical and chemical methods have been developed to access SACs by varying the interaction between metal centers and the coordination defects of the supports. The common challenges for SACs in industrial applications are accurate control over the local structure of single sites and increasing the active-site density. On one hand, the rational design of the atomic structure is decisive to their intrinsic activity, which will affect the adsorption and activation of reactants over the single sites. On the other hand, increasing the metal loading of SACs would largely enhance the density of active sites and the corresponding mass activity, especially for industrial applications. Here, approaches to the synthesis of SACs-focusing on these two challenges-are highlighted.