Profound synergetic effect of metal oxide promoters and TiO₂–SiO₂ binary support in cobalt Fischer‐Tropsch catalyst

Abstract

A series of cobalt catalysts supported on TiO 2 , SiO 2 , or a mixture of them, incorporated with some added oxides from Groups III, IV, and V of transition metals, were prepared using the incipient wetness impregnation method. For better evaluation of catalysts, the physicochemical properties of catalysts were investigated using brunauer-emmett-teller (BET), H 2 -TPR, NH 3 -TPD, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy techniques. The performance of catalysts was studied in a fixed-bed reactor at 220 C, 24 bar, gas hourly space velocity (GHSV) of 2 L/h/gcat., and H 2 to CO ratio of 2. The results indicate that CeO 2 and ZrO 2 as promoters can enhance the CO conversion and catalyst activity and enhance the selectivities of higher-molecular-weight products. On the contrary, the presence of V 2 O 5 as a promoter undesirably suppressed CO conversion and, consequently, catalytic performance. The results show that the catalyst included CeO 2 , was supported on a binary mixture of SiO 2 and TiO 2 , and has significant improved activity and C 5 + selectivity. From the reactor test, values of 156.48 mmol COconv./gCo/h activity, and 0.17 gC 3 + / (h.gcat.) productivity have been obtained for this catalyst. K E Y W O R D S binary support,