(445e) Isomerization of n-Hexane Over MOF-5 Supported Molybdenum Carbide

Highly branched alkanes are more valuable for use in transportation fuels due to their higher octane numbers (ON) when compared to linear alkanes. Isomerization is important for the conversion of normal straight-chain alkanes into branched isomers for additional feedstock and gasoline blending.

Molybdenum based catalysts are active [1-3] for the isomerization of alkanes, including n-hexane. Metal-organic frameworks (MOFs) are attractive for use as catalysts or supports due to their very high surface areas. These supports could lead to high metal dispersions and high loadings, but with significant amount of surface area losses [4-5].

In this paper, we prepared a series of MOF-5 supported Mo2C catalysts using wetness impregnation method. The resulting materials were of up to 2700 m2/g of BET surface area, and their performance characteristics in n-hexane isomerization were compared with those for Mo2C and MoO3 catalysts. The isomerization was performed at 300 °C and 1 atm. Results showed that iso-hexane was the major isomerization product over the MOF-5 support and MoO3 catalysts. The cracking products, including ethane, propane, 1-butene, butane, and pentane, were formed over all catalysts. Small amount of C6+ products were found, including heptane, cyclopentane, cyclohexane, toluene, and p-xylene.

Ref:

1.R. Wehrer, C Bigey, and L. Hilaire, Applied Catalysis A, 243 (2003), 109

2.C. Bouchy, C. Pham-Huu, B. Heinrich, C. Chaumont, and M. J. Ledoux, Journal of Catalysis, 190 (2000), 92

3.A.-F. Lamic, C.-H. Shin, G. Djega- Mariadassou, and C. Potvin, Applied Catalysis A: 302 (2006), 5

4.M. Muller, S. Hermes, K. Kahler, M. W. E. van den Berg, M. Muhler, and R. A. Fischer, Chemistry of Materials , 20 (2008), 4576

5.Tamao Ishida, Megumi Nagaoka, Tomoki Akita, and Masatake Haruta, Chem. Eur. J., 14, (2008) 8456