THE EFFECT OF Mn, Al DOPING ON THE CO2 HYDROGENATION PERFORMANCE OF CaCO3-SUPPORYED Fe-BASED CATALYSTS.

With increasingly serious environmental problems caused by the greenhouse effect, it has also become essential to reduce the concentration of CO2 in the atmosphere. In this paper, CaCO3-supported Fe-based catalysts doped with Mn, Al, and K are prepared by a straightforward method and used for CO2 hydrogenation. The fresh and spent catalysts were characterized by SEM-EDS, BET, TG, CO2-TPD, XRD, and XPS. The experimental results show that the highest CO2 conversion rate of Fe10Mn2Al10Ca is 35.99%, the maximum FTY value is 293.98 μmolCO2·g-1 Fe·s-1, the maximum O/P value is 6.61, and the lowest CO selectivity is 32.21%. At the same time, according to the characterization results, the doping of Mn and Al increased the Fe3O4/FeCx ratio. As the Fe3O4/FeCx ratio increases, the proportion of short-chain hydrocarbons (CH4, C2-4) in the products increases, and the proportion of long-chain hydrocarbons (C5+) decrease. Therefore, the co-doping of Mn and Al promotes the conversion of CO and reduces its selectivity, and promotes the formation of light olefins. Finally, it is hoped that this study can provide a reference for further research on CaCO3-supported Fe catalysts.
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