Effect of Silylation and Support Porosity of Co/MCM-41 and Co/SiO2 Catalysts in Fischer-Tropsch Synthesis

摘要

The effect of silylation in the performance of cobalt catalysts supported on mesoporous silica MCM-41 and non-porous silica in Fischer-Tropsch synthesis (FTS) at process conditions (240 degrees C, 10 bar, H-2/CO ratio = 2.15) was evaluated. Catalysts with a concentration of 5 % metallic phase were synthesized by wet impregnation on silylated and non-silylated supports. The catalysts were characterized by nuclear magnetic resonance, X-ray diffraction, N-2-adsorption/desorption, temperature programmed reduction, diffuse reflectance spectroscopy in the ultraviolet visible region and high resolution transmission electron microscope. The characterization analyses showed the silylation treatment cause disorganization and partial blockage in the structure of MCM-41 support. Consequently, it were observed less CO overall conversion and selectivity towards C5+ hydrocarbons compared with the FTS catalyst prepared with non-silylated support. Also, according to the results of the catalytic evaluation, CO overall conversion seems to be related to the accessibility of the reactants, whereas log-chain hydrocarbons selectivity relates to the ability to reinsert olefins, in conjunction with metal particle size, which is directly connected with metal-support interaction.