CHARACTERIZATION AND ACTIVITY OF COBALT BASED SBA-15 SUPPORTED CATALYSTS FOR CARBON DIOXIDE HYDROGENATION

Abstract

Utilization of renewable energy sources is future solution for providing the word energy demand and to solve the problems of climate changes. Carbon dioxide is greenhouse gas and major contributor to the global warming. Hydrogenation process of carbon dioxide with renewable hydrogen will not only mitigate the problem of global warming but will also produce valuable products and renewable energy. The hydrogenation of carbon dioxide to value-added chemicals and fuels is a promising route, providing products such as carbon monoxide, methanol, hydrocarbons, and higher alcohols. Among these, the synthesis of higher alcohols from carbon dioxide hydrogenation is a challenging task. The literature showed that Co3O4 catalysts with ordered mesoporous structure could promote the growth of carbon chains for higher hydrocarbon and alcohol production. In our study the cobalt based catalysts Co3O4 on SBA-15 support (mesoporous silica) - Co3O4/SBA-15, K/Co3O4/SBA-15 and Pt/Co3O4/SBA-15 - have been prepared and characterized using XRD analysis, N2 adsorption-desorption analysis and SEM-EDX analysis. The results showed that on the contrary from addition of Pt promoter, addition of K promoter decreased the surface area and pore volume, that could be explained with metal oxide dispersion into the pores and on the external surface of the support. CO2 hydrogenation in a fixed-bed tubular micro-activity reactor at 20 bar 250 �C with H2 to CO2 molar ratio 4 to 1 was studied using these catalysts.