Recent Advancements in Graphene-Based Supports of Metal Complexes/Oxides for Epoxidation of Alkenes.

In the past decade, there has been great progress in the preparation and catalytic applications of graphene-supported metal complexes/oxide catalysts. Graphene-based materials have attracted tremendous research interest owing to special physicochemical properties, for example, unique two-dimensional structure, high theoretical specific surface area, high electrical conductivity, and outstanding acid-base resistance properties. Graphene-supported metal complexes/oxides have been extensively investigated, and exhibit good catalytic activity and stability in water splitting (H2 generation or oxygen evolution), oxidation/epoxidation of alkenes, C-C bond formation, and so forth. Herein, recent developments in graphene-supported metal complexes/oxides for the catalytic epoxidation of different alkenes are summarized. Site isolation and synergistic interactions between metal complexes/oxides and graphene are the two key roles for enhancing the catalytic activity, whereas the hydrophobicity of the support can efficiently improve epoxide selectivity. In addition, the possible mechanisms of catalytic epoxidation are summarized. This review provides a feasible scheme for the potential application of graphene-based materials and guidance for the rational design of heterogeneous catalysts for catalytic applications.