Improving Fischer-Tropsch Synthesis Stability, Activity, and Selectivity Using Functionalized CNT-supported Cobalt Catalyst

The influence of functionalizing carbon nanotube (CNT) of CNT-supported nanocatalyst in Fischer-Tropsch synthesis (FTS) has been investigated. The catalysts were synthesized by the wet impregnation of 10 wt. % of cobalt loading over CNT and functionalized CNT. The catalysts were characterized by using BET، XRD، H2 chemisorption، TPR، and TEM. According to the TEM analysis، smaller cobalt particles (3-8 nm) synthesized on functionalized CNT had very narrow particle size distributions and were mostly confined inside the CNT. The deposition of cobalt nanoparticles synthesized on functionalized CNT shifted the reduction peaks to a lower temperature، indicating higher reducibility of uniform cobalt particles. Using the proposed functionalized CNT-supported cobalt catalyst increased the FTS rate (g HC/gcat. /hr)، Co conversion (%)، and C5+ selectivity (%) from 0. 35 to 0. 43، 52. 8 to 62، and 85 to 90 respectively; however، CH4 selectivity (%) decreased from 11 to 5 compared to that of the catalyst prepared on conventional CNT. This new catalyst preparation method may offer an attractive alternative approach to nanoparticle synthesis with uniform and various size distributions.