The modification of SiO2 by various organic groups and its influence on the properties of cobalt-based catalysts for Fischer-Tropsch synthesis

摘要

SiO2 was modified by various organic groups before the impregnation of cobalt precursor. These modified supports and the corresponding catalysts were characterized by BET, ~(29)Si CP MAS NMR, XRD, Raman, XPS and H2-TPR. These characterizations clearly show the changes of morphology as well as reducibility of the catalysts. The organic modification of SiO2 remarkably influences the reducibility and catalytic properties of Co catalysts. Co catalyst supported on (CH3)3-modified SiO2 exhibits high activity and C5~+ hydrocarbon selectivity. However, COOH-, NH2-, and NH2(CH2)2NH-modified SiO2 distinctly suppress the catalytic activity of Co catalysts.