Effect of Manganese Promotion on Al-Pillared Montmorillonite Supported Cobalt Nanoparticles for Fischer-Tropsch Synthesis

The effect of Mn-promotion on high surface area Al-pillared montmorillonite (AlMMT) supported Co nanoparticles prepared by hydrothermal method have been investigated. A series of different weight % Mn-promoted Co nanoparticles were prepared and characterized by XRD, TPR, TGA, BET and SEM techniques. An increase in the surface area of MMT is observed with Al-pillaring. Fischer-Tropsch catalytic activity of the as prepared catalysts was studied in a fixed bed micro reactor at 225 oC, H2/CO = 2 and at 1 atm pressure. The data showed that by the addition of Mn the selectivity of C1 dropped drastically while that of C2-C12 hydrocarbons increased significantly over all the Mn-promoted Co/AlMMT catalysts. The C13-C20 hydro-carbons remained almost same for all the catalysts while the selectivity of C21+ long chain hydrocarbons decreased considerably with the addition of Mn. The catalyst with 3.5%Mn showed lowest C21+ and highest C2-C12 hydrocarbons selectivity due to cracking of long chain hydrocarbons over acidic sites of MMT