Selective hydrodeoxygenation of 5-hydroxy-2(5H)-furanone to γ-butyrolactone over Pt/mesoporous solid acid bifunctional catalyst

Abstract

Selective hydrodeoxygenation of 5-hydroxy-2(5H)-furanone (HFO) derived from furfural oxidation to γ-butyrolactone (GBL) provides a sustainable alternative to the petroleum-based process for γ-butyrolactone production. Furfural is first converted to HFO through selective photocatalytic oxidation by using air oxygen as the oxidant (yield: 85.0%). HFO is further converted to GBL through hydrodeoxygenation over noble-metal nanoparticles on mesoporous Nb–Zr mixed oxides. The conversion of HFO to GBL involves two reactions: hydrogenation catalyzed by active metal and dehydration over mesoporous solid acids. The catalytic properties of M/Nb–Zr mixed oxides (M = Pt, Ir, Ru, Rh and Pd) are related to the composition of support and active metal. The incorporation of zirconia into matrixes improves the thermal stability of mesoporous mixed oxides and increases the amounts of surface acid, which contributes to its catalytic selectivity to GBL. Pt/Nb₅Zr₅-550 exhibited the best catalytic performances with 97.3% selectivity of GBL at full conversion. The excellent performance can be correlated with the cooperative effect between active metal species and acid sites. The Pt-solid acid bifunctional catalysts show superior catalytic performance compared with conventional catalysts, such as Pt/H-ZSM-5, Pt/C, Rh/C or Pd/C. An overall GBL yield of 82.7% from furfural was obtained.