Phosphotungstic acid supported on Zr-SBA-15 as an efficient catalyst for one-pot conversion of furfural to γ-valerolactone

Development of high-performance solid catalysts for the utilization of biomass has become an important research topic in heterogeneous catalysis and sustainable chemistry. Herein, A series of phosphotungstic acid (HPW) supported on Zr-SBA-15 were prepared by a post-synthesis procedure and evaluated for the one-pot conversion of furfural (FUR) to γ-valerolactone (GVL) using 2-propanol as the H-donor and solvent. Those catalysts were detailed and characterized by XRD, N2 physisorption, FTIR, SEM, TEM, NH3-TPD, and pyridine-DRIFT techniques. Among those catalysts, a complete conversion of FUR was achieved, while the selectivity of GVL was significantly affected by the ratio of HPW and Zr. The HPW/Zr-SBA-15 (2-4-15) (the mass ratio of HPW: ZrOCl2: SBA-15 = 2:4:15) showed the highest GVL yield (83%) under optimized reaction conditions. Correlating the catalyst performance with the B/L ratio (Brønsted acid sites (BAS)/Lewis acid sites (LAS)) ratio uncovers that the balance between the BAS and LAS would be the key to higher catalytic performance. Different reaction parameters including reaction temperature, time, and FUR concentration were also studied. In addition, the catalyst showed good stability and regeneration.