High efficiency catalytic transfer hydrogenation of ethyl levulinate to γ-valerolactone over Hf-based catalyst

The transformation of biomass platform compounds to value-added products is of great significance in biomass development. Herein, a series of wHfO2/SBA-15 (w = 0.7-12.5 wt%) catalysts were synthesized and applied to the catalytic transfer hydrogenation (CTH) of ethyl levulinate (EL) to gamma-valerolactone (GVL) reaction. The physicochemical properties of the prepared samples have been characterized by XRD, N2 adsorption-desorption, ICP, FT-IR, SEM, TEM, XPS, UV-vis, 29Si NMR, NH3-TPD, and Pyridine-FTIR. The introduction of hafnium species could produce abundant Lewis acid sites (LAS) without altering the ordered mesoporous structure of SBA-15. In addition, part of Hf species entered the SBA-15 framework and formed a small amount of Br & oslash;nsted acid sites (BAS). Among these catalysts, 10.4HfO2/SBA-15 showed an excellent catalytic performance, providing a very high EL conversion (96 %) and GVL selectivity (91 %) at 130 degrees C in 3 h using isopropanol as the H-donor. The high catalytic performance maybe related to the high surface area and large amount of LAS. Furthermore, this catalyst also showed a good stability and reusability.