Synthesis of SiO2-stabilized FeMn catalysts for catalytic production of liquid fuels: effect of SiO2 position over bimetallic catalysts

• Published in: Journal of porous materials 2022-12, Vol.29 (6), p.1797-1806
• Main Authors: Zhang, Yulan, Lin, Xizhu
• Format: Article
• Language: English
• Subjects: Bimetals; Carbon monoxide; Catalysis; Catalysts; Catalytic activity; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry; Chemistry and Materials Science; Fischer-Tropsch process; Liquid fuels; Optimization; Physical Chemistry; Selectivity; Silicon dioxide
• ISSN: 1380-2224; 1573-4854
• DOI: 10.1007/s10934-022-01288-0

Fischer-Tropsch synthesis (FTS) is a non-petroleum-based alternative route for direct production of liquid fuels. Promoters are required to attain optimum catalytic performance; however, the strong metal-promoter interaction limits the catalytic activity. To optimize the selectivity-promoting property, two different SiO 2 -stabilized core-shell catalysts were designed via tuning the position of SiO 2 shell. Clearly, the research on SiO 2 -stabilized and Mn-promoted core-shell catalyst is still insufficient. It demonstrates that the C 5+ yield over SiO 2 -incorporated FeMnSi (13.7 × 10 −4 g HC g Fe −1 s −1 ) and FeSiMn (20.8 × 10 −4 g HC g Fe −1 s −1 ) is higher than that of unstabilized FeMn catalyst (2.85 × 10 −4 g HC g Fe −1 s −1 ). Interestingly, the CO conversion over the three catalysts obeys the following role: FeSiMn > FeMnSi > FeMn. The better C 5+ production with high catalytic activity over FeSiMn is correlated with the critical role of Mn-improved spillover effect. This is because the formed MnFe 2 O 4 over FeMnSi and FeMn catalyst limits the initial catalytic performance, and that can gradually suppress CO dissociation and hinder chain growth. Controlling the metal-promoter interaction in FT synthesis can better understanding and rational design of a catalyst with enhanced catalytic performance.