Zirconia and Phosphotungstic Acid Supported on TS-1 as An Active Catalyst for One-Pot Selective Conversion of Furfuryl Alcohol to γ-Valerolactone

Abstract

Gamma-valerolactone (GVL) has been identified as a sustainable high-value platform molecular for the production of fuels and carbon-based chemicals. In this work, a novel bifunctional Zr-P/TS-1 catalyst with Brønsted and Lewis acidic sites that enables an efficient one-pot conversion of furfuryl alcohol (FAL) into GVL has been developed by loading ZrO2 and phosphotungstic acid on TS-1. A GVL selectivity of 85.2% at FAL conversion of 100% could be achieved at 170 °C in 24 h over 30Zr-10P/TS-1 using 2-propanol as the hydrogen donor and solvent. Through XRD, TG-DTG, NH3-TPD, SEM, EDS and XPS analysis, the synergistic effect of multiple functional sites is responsible for the good catalytic activity of the catalyst. Based on products distribution, reasonable reaction pathways and mechanisms have been proposed. Brønstedacidic sites of phosphotungstic acid promotes the conversion of furfuryl alcohol to isopropyl levulinate via intermediate isopropyl furfuryl ether in the reaction, and the Lewis acidic sites of ZrO2 effectively catalyzes the transfer hydrogenation of isopropyl levulinate to GVL. Moreover, the 30Zr-10P/TS-1 catalyst was reused for four cycles and exhibited good stability.