Keywords

Catalysts, alumina supports, cobalt, Fischer-Tropsch

Abstract

Four identically-prepared 20 wt% cobalt/0.15 wt% ruthenium Fischer-Tropsch catalysts, supported on different aluminas, were synthesized by incipient wetness impregnation, characterized, and compared based on their performance under standard Fischer-Tropsch synthesis conditions. Three alumina supports were obtained from commercial sources (Sasol, St. Gobain, and Alfa Aesar), while the fourth was made using a published technique that included 5 wt% silica. The silica-stabilized alumina catalyst produced superior Fischer-Tropsch rates of 49 mmol CO/gcat h, compared to the other catalysts on the commercial supports with rates of 26–39 mmol CO/gcat h. The improved performance of the silica-stabilized alumina support compared to the commercially available aluminas is ascribed to a bimodal pore structure with larger average diameters and enhanced thermal stability. The support can be thermally treated to higher temperatures (e.g., 1100 C) without transformation into a-alumina, allowing dehydroxylation of the surface prior to impregnation to stabilize a nearly ideal dispersion of cobalt crystallites.

Original Publication Citation

Rahmati, M., B. Hong, M. K. Mortenson, K. Keyvanloo, W. C. Hecekr, T. H. Fletcher, and M. D. Argyle, “Effect of Different Alumina Supports on Performance of Cobalt Fischer-Tropsch Catalysts,” Journal of Catalysis, 359, 92-100 (2018). DOI: 10.1016/j.jcat.2017.12.022