Advances of Single-Atomic Cobalt Catalysts in Liquid-Phase Selective Oxidative Reactions

Abstract

Single-atom catalysts (SACs) composed of atomically dispersed metal-active sites embedded in supporting substrates are attracting increasing attention in liquid-phase selective oxidation reactions with joint merits of both advanced catalytic efficiency and high stability. Co-based SACs present superior performance in several model oxidative reactions against many other metals, thus they are recognized as a promising solution to the current high-cost noble-metal catalysts required for the synthesis of fine chemicals. In this review, the up-to-date research on the synthesized Co–SACs in selective oxidation applications is summarized. The strategies of the preparation of Co–SACs with diverse Co-loading levels and well-tuned morphologies and chemical structures are showcased, as well as the characterization techniques of the SACs. The applications of Co–SACs in a series of selective oxidation reactions and the influence of different oxidants on the overall reaction efficiency are discussed. In addition, the progress of the mechanism exploration involving active-site identification, catalytic activation of oxidants, and oxidation pathway elucidation is highlighted. Meanwhile, the existing challenges and the future efforts for the development of the Co–SAC reaction system in selective oxidation processes are outlined.