Outlook of Cobalt-Based Catalysts for Heterogeneous Hydroformylation of Olefins: From Nanostructures to Single Atoms

Hydroformylation of olefins, as a study of olefinic downstream derivative production, is of great relevance in chemical production. Heterogeneous hydroformylation is beneficial for catalyst separation and recycling compared to homogeneous systems. Cobalt is a cheap metal with excellent catalytic activity in hydroformylation as well as the precious metal rhodium. Therefore, the research on cobalt-based catalysts for heterogeneous hydroformylation has great value and significance. The nano or atomic structures of cobalt-based catalysts have significant impact on the catalytic behaviors of the hydroformylation process. There is rarely the design principles report on how to achieve significant improvement in hydroformylation performance by regulating the structure of the cobalt-based catalyst. Herein, we review the recent research progress on heterogeneous hydroformylation by cobalt-based catalysts with different metal sizes (from nanostructures to single atoms). On the basis of the difference in the catalytic mechanism between homogeneous and heterogeneous hydroformylation, we summarize and propose the regulation principles to enhance the activity and stability of cobalt-based catalysts in hydroformylation, where single-atom engineering is expected to achieve unity of high activity and stability of cobalt-based catalysts for hydroformylation applications. At the end of this review, we present an outlook on the opportunities and challenges in developing cobalt-based catalysts for heterogeneous hydroformylation.