Ali Karimi - Gas Research Division, Research Institute of Petroleum Industry, Tehran, Iran
Ahmad Tavasoli - School of Chemistry, College of Science, University of Tehran, Tehran, Iran
Ali Mohajeri - Gas Research Division, Research Institute of Petroleum Industry, Tehran, Iran
Yahya Zamani - Gas Research Division, Research Institute of Petroleum Industry, Tehran, Iran

In this research, γ-Alumina was pretreated in the presence of phosphoric acid-ethanol, and then used to prepare the supported cobalt catalysts for Fischer-Tropsch synthesis (FTS). Different concentrations of phosphoric acid were applied for pretreatment of γ-Alumina to modify it's surface properties. The catalysts were prepared by incipient wetness impregnation of the cobalt precursor, and deionized water was used as preparation medium. The reduction degree and dispersion of γ-alumina-supported cobalt catalyst were improved through this pretreatment. The obtained catalysts were characterized by FTIR, NH3-TPD, XRD, TPR, TEM and H2 chemisorption. These characterizations clearly showed the changesof morphology (surface area, pore volume, pore size distribution and crystallite phase) as well as chemical properties (e.g. acidity) of the supports. Optimize the support pretreatment parameters exhibited significant catalyst's stability and activity, applying to FTS reaction in CSTR reactor during 320 h test.

γ-Alumina, Cobalt catalyst, Fischer–Tropsch synthesis, Phosphoric acid, Activity and stability