Supported Iron Fischer–Tropsch Catalyst: Superior Activity and Stability Using a Thermally Stable Silica-Doped Alumina Support

• Published in: ACS catalysis 2014-04, Vol.4 (4), p.1071-1077
• Main Authors: Keyvanloo, Kamyar, Mardkhe, Maryam Khosravi, Alam, Todd M, Bartholomew, Calvin H, Woodfield, Brian F, Hecker, William C
• Format: Article
• Language: English
• ISSN: 2155-5435; 2155-5435
• DOI: 10.1021/cs401242d

Fischer–Tropsch synthesis (FTS) is a technically proven and economically viable route for the conversion of coal, biomass, and natural gas to hydrocarbon fuels. Although unsupported Fe catalysts are proven for FTS, they lack the physical strength and durability that would make them more viable for large-scale commercial reactors, and their activity is still significantly less than that of Co FT catalysts. In this work, we report on a very active and stable supported Fe FT catalyst that is more active than any supported Fe FT catalyst previously reported and competitive with the best unsupported catalysts. In addition, its productivity, which takes into account selectivity to desired hydrocarbon products, is also very competitive. More importantly, the catalyst is extremely stable, as evidenced by the fact that after 700 h on stream, its activity and productivity are still increasing. These catalyst properties result from using a novel γ-alumina support material doped with silica and pretreated at 1100 °C. This unique support has high pore volume, large pore diameter, and unusually high thermal stability. The ability to pretreat this support at 1100 °C enables preparation of a material having a low number of acid sites and weak metal oxide–support interactions, all desirable properties for an FT catalyst. These results demonstrate that the surface chemistry of the support material plays a crucial role in the design of an active and stable supported Fe FT catalyst.