Hydrodeoxygenation of cyclic vicinal diols such as 1,4-anhydroerythritol was conducted over catalysts containing both a noble metal and a group 5–7 transition-metal oxide. The combination of Pd and WOx allowed the removal of one of the two OH groups selectively. 3-Hydroxytetrahydrofuran was obtained from 1,4-anhydroerythritol in 72 and 74 % yield over WOx–Pd/C and WOx–Pd/ZrO2, respectively. The WOx–Pd/ZrO2 catalyst was reusable without significant loss of activity if the catalyst was calcined as a method of regeneration. Characterization of WOx–Pd/C with temperature-programmed reduction, X-ray diffraction, and transmission electron microscopy/energy-dispersive X-ray spectroscopy suggested that Pd metal particles approximately 9 nm in size were formed on amorphous tungsten oxide particles. A reaction mechanism was proposed on the basis of kinetics, reaction results with tungsten oxides under an atmosphere of Ar, and density functional theory calculations. A tetravalent tungsten center (WIV) was formed by reduction of WO3 with the Pd catalyst and H2, and this center served as the reductant for partial hydrodeoxygenation.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.