Hydroformylation of 1-Hexene over Co/SiO2 Catalysts: Influence of Pore Size of Support.

Silica-supported cobalt catalyst was studied for hydroformylation of 1-hexene. The influence of pore size of the silica support was investigated. It was found that cobalt catalyst supported on silica with appropriate pore size, about 6-10 nm, was active for the reaction with very high selectivity to oxygenates. The smaller the pore size and the higher the surface area of the silica support, the higher metal dispersion and the smaller the cobalt particle size. But, in turn, the reducibility of the supported cobalt was lower. The cobalt catalyst supported on silica with small pore size seemed to be more stable during the reaction due to the interaction between cobalt particles and the support. Although there might be homogeneous reaction on the dissolved cobalt species, the activity was mainly from the heterogeneous hydroformylation of 1-hexene.