Synthesis and Characterization of Silica Supported Co/Nb Bimetallic Catalyst for the Production of Synthetic Fuel via Fischer-Tropsch

Fischer Tropsch synthesis has received considerable attention as it offers a viable alternative to produce liquid fuels and chemicals from non-petroleum carbon resources such as biomass, coal and natural gas. The objective of this work is to synthesize, characterize and study the performance of supported bimetallic cobalt (Co) and niobium (Nb) catalyst in Fischer Tropsch synthesis. Supported bimetallic Co and Nb catalyst have been formulated using reverse microemulsion method. 5wt% of nano particles metal loadings were deposited on silica (SiO2) support. The effect of different metal loading composition of Co and Nb (100:0, 95:5, 90:10, 85:15) on the physiochemical properties of the catalyst has been investigated. The physiochemical properties of the catalyst were studied using field emission electron microscopy (FESEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and N2 physical adsorption. The FTS performance of the synthesized catalyst was examined in a fixed-bed Microreactor at 220oC, atmospheric pressure and H2/CO ratio of 2:1. Results from the N2 physical adsorption shows that addition of niobium decreases the pore area and volume. It also changes the textural structure from non porous to porous. FESEM and TEM results have shown that the metal particles are well dispersed on the support. The average particle sized ranges from 10.61 nm - 25.5 nm. Introduction of niobium to the catalyst changes its shape from spherical to hexagonal and forms fringes on the particles. This indicates the crystalline structure of cobalt particles. The FTS results exhibit that the CO conversion increases with the amount of Nb in the catalyst. The highest CO conversion is obtained from Sample D (85Co15Nb) which is 70.07%. Sample B (95Co5Nb) showed the lowest selectivity towards CH4 (6.58%) and highest selectivity towards C5+ hydrocarbons i.e. 8.79%. All the samples catalysts display high olefin productivity, indicating that the catalysts synthesized are more suitable for olefin production.