Catalytic Properties for Mixed Alcohols Synthesis and Structure of Co-K-Mo/γ-Al2O3 Catalysts

A series of oxidic Co-K-Mo/gamma-Al2O3 catalyst samples, prepared by impregnating oxidic K-MoO3/gamma-Al2O3 samples with aqueous solution of calculated Co (NO3)(2) and then calcination in air at temperatures of 350 degrees C, 500 degrees C, 650 degrees C and 800 degrees C, respectively, were sulfided and then investigated for the; thesis of mixed alcohols from CO and GHSV=4800(h-1). The results hydrogenation at conditions of p=5.0MPa, T=350 degrees C demonstrate that the addition of cobalt promoter is favourable to from higher alcohols d the samples calcined at 500-600 degrees C after impregnating Co2+ possess superior properties for the mixed alcohols synthesis. The structures of Co d Mo species on the oxidic sulfided samples were determined by XRD, LRS and EXAFS. For oxidic sample calcined at 350 V, cobalt exists as Co3O4 species and covers on the surface of K-M0-O species, the structures of K-Mo-O species are same as that in K-MoO3/gamma-Al2O3 sample. After sulfidation, cobalt exists as sulfide crystallites with octahedral coordinated Co, d Mo as MoS2 crystallites, For oxidic samples calcined at 500-650 degrees C. Co component interacts with the K-Mo-O species and destroys the long-range order of the K-Mo-O species gradually After sulfidation, Co tends to be existed as a sulfide with tetrahedral coordinated Co and Mo still as MoS2 crystallites. For oxidic sample calcined at 800 degrees C, Co component exists mainly as Co(Al2O4) species, most of which can not be sulfided during sulfidation,