Energy & Fuels, Vol.34, No.6, 7190-7197, 2020
Selective Hydrodeoxygenation of gamma-Valerolactone over Silica-supported Rh-based Bimetallic Catalysts
2-Methyltetrahydrofuran (2-MTHF) is a promising fuel additive and renewable solvent. Herein, we report a selective hydrodeoxygenation of cellulose-derived gamma-valerolactone (GVL) to 2-MTHF under mild conditions over silica-supported RhRe and RhMo bimetallic catalysts. RhMo/SiO2 showed the best performance for the target 2-MTHF with a high selectivity of 86% in heptane at 120 degrees C. The high catalytic performance of Rh-based catalyst was attributed to an acidity induced by the presence of additional metals such as Mo or Re. However, the acidity in aqueous phase was weaker than that in heptane, requiring additional acid sites. ZSM-5 performed best in combination with the bimetallic catalysts, resulting in the selectivity of 76% to 2-MTHF even in water at 120 degrees C. Moreover, a high reaction temperature (160 degrees C) caused hydrodeoxygenation of 2-MTHF and enabled perfectly selective production of alkanes with butane and pentane as predominant products.