Preparation,Characterization,and Mechanism Research Of The Catalyst For F-T Performance:Cobalt Carbonyl Clusters And Re-cobalt Carbonyl Clusters Bridged Complex As Catalyust Precursors

The Fischer-Tropsch Synthasis(F-T Synthesis)converts synthesis gas(CO + H2)into clean liquid fuels.It is vital importance for reducing greenhouse gas emission.Metallic carbonyl cluster precursors loaded on oxides supports are of great potential F-T synthesis catalysts because it possess a higher and more uniform metal dispersion and superior catalytic properties than that of the corresponding conventional metal salt catalyst.In this dissertation,various cobalt carbonyi cluster was synthesized,which have been acted as precursors for preparing γ-Al2O3 supported catalysts.Detailed results are summarized as follows:1.(CO)6Co2HCCCOOH and(CO)6Co2CC(COOH)2 were synthesized based on the literature.Co2-COOH/γ-Al2O3 and Co2-(COOH)2/γ-Al2O3 were prepared by the conventional wet-impregnation method.Effects of different carboxyl groups were compared with FTS,In-situ IR,TPD-MS,TEM,XPS and structure evolution was speculated.Experimental studies show that the structure mainly affect activity of catalyst,the numbers of carboxyl groups mainly affect selectivity of C5+.2.A series of catalysts were prepared by impregnating(CO)6Co2HCCCOOH,(CO)9Co3CCOOH and(CO)10Co4HCCCOOH precursors on y-Al2O3 support,labeled as:Co2/γ-Al2O3Co3/γ-Al2O3 andCo4/γ-Al2O3.Combined with the characterization of In-situ IR,TPD-MS,TEMand XPS techniques,the evolution of the catalysts under H2 atmosphere were speculated.The catalytic performance of these catalysts for FTSwas also tested.The results indicating the degree of interaction between the Co2/γ-Al2O3,Co4/γ-Al2O3 and the support was equivalent which led to the similar cobaltdispersion for the Co2/γ-Al2O3,Co4/γ-Al2O3.3.The cobalt carbonyl cluster-Cerium bridged complex was designed and loaded onto γ-Al2O3.At the same time,Co+Ce/γ-Al2O3 was prepared with the mechanical mixture method.The purpose of this work was to compare the mode of adding promoter.These catalysts were characterized with In situ IR,Ar-TPD-MS,CO-TPD,TPR,XRD,XPS.The reason of deactivation has been studied.4.In order to impove the activity of Co/γ-Al2O3 catalyst for FTS,3 kinds of lanthanide metals(La、Ce、Sm)were employed to synthesis a series of cobalt carboyl cluster-lanthanide bridged complex as promoters.The effect of rare earth on the activity of the catalysts were evaluated by TEM and XPS.