Selective Hydrodeoxygenation of γ‑Valerolactone\nover Silica-supported Rh-based Bimetallic Catalysts

Abstract

2-Methyltetrahydrofuran\n(2-MTHF) is a promising fuel additive and\nrenewable solvent. Herein, we report a selective hydrodeoxygenation\nof cellulose-derived γ-valerolactone (GVL) to 2-MTHF under mild\nconditions over silica-supported RhRe and RhMo bimetallic catalysts.\nRhMo/SiO₂ showed the best performance for the target 2-MTHF\nwith a high selectivity of 86% in heptane at 120 °C. The high\ncatalytic performance of Rh-based catalyst was attributed to an acidity\ninduced by the presence of additional metals such as Mo or Re. However,\nthe acidity in aqueous phase was weaker than that in heptane, requiring\nadditional acid sites. ZSM-5 performed best in combination with the\nbimetallic catalysts, resulting in the selectivity of 76% to 2-MTHF\neven in water at 120 °C. Moreover, a high reaction temperature\n(160 °C) caused hydrodeoxygenation of 2-MTHF and enabled perfectly\nselective production of alkanes with butane and pentane as predominant\nproducts.