Observation of Cobalt Species Evolution in Mesoporous Carbon by In-Situ STEM-HAADF Imaging and Related Hydrogenation Process

Metal decorated-mesoporous carbons (MMCs) has attractive features from both mesoporous materials (large pore size, high pore volume) and metal species (reactive surface). Cobalt@mesoporous carbon (Co@MC) catalyst was successfully manufactured by mechanochemical synthesis method for hydrogenation of phenol to prepare cyclohexanone. Unlike traditional hard-templating and soft-templating methods, the essence of this strategy lies in the combination of carbonization and ligand-protected metal reduction. By using Fourier transform-infrared spectroscopy, X-ray diffraction and N-2 adsorption-desorption, Co@MC catalyst was well studied. In particular, the effect of calcination temperature in terms of growth and aggregation of cobalt species was detailly explored by in-situ scanning transmission electron microscopy-high angle angular dark field. A series of mesoporous carbons with cobalt species readily tuned from clusters to nanoparticles were measured in phenol hydrogenation (Conv. Phenol: >99 %, Sel. Cyclohexanone: >99 %).

Automated summary

Metal decorated-mesoporous carbons (MMCs) combine the advantages of mesoporous materials and metal species. A cobalt@mesoporous carbon (Co@MC) catalyst was successfully synthesized, and the effect of different calcination temperatures on cobalt species was studied. The Co@MC catalyst showed high phenol conversion and cyclohexanone selectivity in the phenol hydrogenation reaction.