Dynamics-driven tailoring of Zr-embedded hierarchical ZSM-5 zeolites for enhanced catalytic performance from furfural to alkyl levulinate

Abstract

The tandem reaction for generation of alkyl levulinate (AL) from bio-derived furfural (FUR) is environmental-friendly, in which the bifunctional catalyst with both metal active sites and acid sites are required. In this contribution, a MFI-type nanosponge zeolite with Zr-Al co-framework (Zr@NPZ) were one-pot hydrothermally synthesized using dual-template method. Series characterizations demonstrate that, highly dispersed Zr species embeds in the hierarchical zeolite framework and exhibits typical Lewis acids. Using isopropanol as solvent, Zr@NPZ catalyst gives isopropyl levulinate (IPL) yield up to 75.5 wt% at 180 °C after 2 h reaction from FUR, through sequenced transfer hydrogenation and hydrolysis, with production rates of 11.5 mmol g−1h−1. Moreover, although the enhanced acidities accelerate the conversion rates of FUR, the generation of β-angelica lactone (AGL) from 2-(isopropoxymethyl)furan (IPMF) and conversion of IPL to γ-valerolactone (GVL) are promoted, sacrificing the yield of IPL in the product. The synergism between high dispersed Zr species and moderate acid distribution lead to relative high yield of target IPL.