Fischer–Tropsch Synthesis: Studies on the Effect of Support Doping with Si, Mn and Cr on the Selectivity to Alcohols in Ceria Supported Cobalt Catalysts

• Published in: Topics in catalysis 2014-04, Vol.57 (6-9), p.550-560
• Main Authors: Ribeiro, Mauro C., Gnanamani, Muthu K., Azevedo, Israel R., Rabelo-Neto, Raimundo C., Jacobs, Gary, Davis, Burtron H., Noronha, Fabio B.
• Format: Article
• Language: English
• Subjects: Catalysis; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Industrial Chemistry/Chemical Engineering; Original Paper; Pharmacy; Physical Chemistry
• ISSN: 1022-5528; 1572-9028
• DOI: 10.1007/s11244-013-0211-2

Mn and Cr doped CeSi mixed oxides were used as supports for Co and tested for CO hydrogenation. Co/CeSi was found to be more active and significantly more selective to n-alcohols/olefins. An increasing selectivity to n-alcohols and decreasing selectivity to olefins as a function of time on stream was also observed, suggesting a trade-off between those two products. Addition of Mn led to similar behavior, although at slightly lower conversions. Addition of Cr, however, considerably suppressed n-alcohol formation, while it kept selectivities to olefins within a 20–30 % range over more than 250 h of testing, indicating either higher alcohol dehydration activity, or that the presence of Cr ions lowered the hydrogenating activity of Co. The present work indicates that enhanced contact area between Co and the reducible support is likely a key factor for enhancing selectivity to alcohols.