The products over conventional Fischer-Tropsch (FT) catalysts generally follow the Anderson-Schulz-Flory (ASF) distribution. Selectivity control remains one of the biggest challenges. We recently succeeded in tuning the product selectivity through reaction coupling with bifunctional catalysts, which can catalyze the hydrogenation of CO on Ru or Co nanoparticles and the selective C-C bond cleavage of the primary heavier hydrocarbons on mesoporous zeolites. The combination of zeolite with FT catalyst led to high C5-C11 (gasoline) selectivity owing to the hydrocracking of the primary heavier hydrocarbons, but the selectivity to undesirable lower alkanes was too high. The use of mesoporous zeolites instead of microporous zeolites suppressed the formation of CH4 and C2-C4 and increased the selectivity to C5-C11 hydrocarbons.[1] The C5-C11 selectivity reached 70-80%, breaking the ASF distribution (~45%). The presence of mesopores plays crucial roles in the selective hydrocracking of heavier hydrocarbons, thus contributing to the high C5-C11 selectivity (Fig. 1). We further discovered that the use of mesoporous zeolite Y (Na-meso-Y) without Brønsted acidity enhanced the formation of C10-C20 (diesel fuel), and the C10-C20 selectivity reached 60%, much higher than that expected from the ASF distribution (39%).[2] We clarified that the hydrogenolysis of heavier hydrocarbons occurred over supported Co catalysts and the effective control of the hydrogenolysis by optimizing the Co particle size and the support mesopore size could significantly enhance the C10-C20 selectivity. References 1. Kang, J.; Cheng, K.; Zhang, L.; Zhang, Q.; Ding, J. S.; Hua, W.; Lou, Y.; Zhai, Q.; Wang, Y. Angew. Chem. Int. Ed. 2011, 50, 5200-5203. 2. Peng, X.; Cheng, K.; Kang, J.; Gu, B.; Yu, X.; Zhang, Q.; Wang, Y. Angew. Chem. Int. Ed. 2015, 54, 4553-4556.

Selectivity control in Fischer-Tropsch synthesis for the production of liquid fuels

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.