The Performance Of Mesporous Oxides Support Supported Co Catalysts For F-T Synthesis

The influence of different SiO₂support and mixed support on the performance ofCo-based catalysts for F-T synthesis was investigated. The physicochemicalproperties of catalysts were characterized with XRD, BET, H2-chemisorption,H2-TPR and Raman spectroscopy. Fix-bed reactor was employed to evaluate theactivity of catalysts under the condition as temperature240℃, pressure2MPa, GasHourly Space Velocity （GHSV）1000h-1.Co-based catalysts with different oxides assupports were prepared and studied, such as SiO₂varying in pore size, mixed oxides,ZrO₂-SiO₂varying in content, and so on. The main research contents and results areas follows:（1） The impact of bimodal SiO₂with different pore size distribution on Co-basedcatalyst for F-T synthesis was studied. Bimodal SiO₂supported Co catalysts exhibitedbetter performance than the ones with single pores. The results showed that COconversion of catalysts depended on the Co particle size, and C₅₊selectivity dependedon the pore size. With the loaded Co increased, CO conversion improved, C₅₊selectivity decreased.（2） Al₂O₃-SiO₂, ZrO₂-SiO₂, TiO2-SiO₂and CeO2-SiO₂mixed oxides weresynthetized with Q50as sources and applied in F-T synthesis. The results showed thetypes of mixed supports had impact on the activity. Co/Al₂O₃-SiO₂, Co/ZrO₂-SiO₂and Co/CeO2-SiO₂catalysts obviously promoted CO conversion,but C₅₊selectivity islower, indicating that the addition of heteroatom oxides such as Al₂O₃, ZrO₂andCeO2played a positive role in the F-T synthesis. At the same time, Co/TiO2-SiO₂performed not so high CO conversion.（3） ZrO₂-SiO₂mixed supports different in ZrO₂mass fraction were prepared withQ50as sources. The loaded Co catalysts were employed in the F-T synthesis. It canbe found that as ZrO₂content grew, CO conversion and C₅₊yield increased firstly andthen decreased, besides, C₅₊selectivity exhibited the opposite tendency. The catalystwith50wt%ZrO₂in the mixed support performed better CO conversion and C₅₊selectivity, which were66.7%,76.1%, respectively.