Continuous production of γ-valerolactone from furfural using optimized catalysts containing Zr and Nb

gamma-Valerolactone (GVL) is a versatile platform molecule that can be produced from furfural (FF), a compound readily obtained from biomass. The transformation of FF into GVL can be achieved in a one-pot process through a cascade of reactions involving hydrogenation, ring opening, dehydration, and cyclization. Designing an appropriate catalyst capable of promoting all these steps in a single system is therefore essential. In this work, catalysts based on zirconium supported on Y-zeolite, as well as catalysts supported on Y-zeolite coated with a theoretical monolayer of Nb2O5, were synthesized and evaluated for the conversion of FF into GVL. Reactivity tests were conducted under both batch and continuous-flow conditions. The catalysts were characterized using various techniques, including XRD, FTIR, IR-Py, DR-UV-Vis, HR-TEM, XPS, and NH3-TPD, to determine their physicochemical properties. Among the catalysts studied, Zr supported on Nb-modified Y-zeolite exhibited the highest catalytic activity, achieving a GVL yield of 65 % after 3 h at 180 degrees C in batch mode using 2-propanol as both hydrogen source and solvent. Similarly, under continuous-flow conditions, this bimetallic catalyst delivered the highest GVL yield (approximately 40 %), representing the best performance reported to date for this reaction. Furthermore, the addition of water to the reaction medium enhanced catalytic performance. Notably, the bimetallic catalyst maintained stable activity throughout the tested time-on-stream.