Silylated Co3O4-m-SiO2 catalysts for Fischer–Tropsch synthesis

Silylated Co 3 O 4 - mesoporous SiO 2 catalysts were prepared by a surface organic modification to understand the influence of a hydrophobic surface on their performance in the Fischer–Tropsch synthesis (FTS). Fourier transform infra-red (FT-IR) spectra showed that the reaction of the surface silanol groups with hexamethyldisilazane (HMDS) took place effectively, and X-ray diffraction (XRD) indicated that such a modification did not affect Co 3 O 4 crystallite size. Furthermore, hydrogen temperature programmed reduction (H 2 -TPR) illustrated a higher extent of reduction for silylated Co 3 O 4 - m -SiO 2 catalysts. As a result, such a silylated core–shell structured Co catalyst showed the higher catalytic activity and better selectivity towards C 5 –C 18 fraction than the unsilylated Co 3 O 4 - m -SiO 2 catalyst in the FTS, which was likely favorable to the internal transportation and their hydrophobic shell. ► Core–shell Co 3 O 4 - m -SiO 2 catalyst could be prepared via the solvothermal method. ► Silylated Co 3 O 4 - m -SiO 2 catalysts could be prepared using HMDS. ► Orangic modification of Co 3 O 4 - m -SiO 2 catalysts could enhance reduction degree. ► Silylated Co 3 O 4 - m -SiO 2 catalysts showed the better C 5 –C 18 selectivity.