Levulinic Acid Production from Waste Corncob Biomass Using an Environmentally Benign WO₃-Grafted ZnCo₂O₄@CeO₂ Bifunctional Heterogeneous Catalyst

Abstract

Herein, a novel and environmentally benign solid catalyst was fabricated by grafting WO 3 active species onto the ZnCo 2 O 4 @CeO 2 support for efficient levulinic acid production from corncob waste biomass. The morphological, compositional, and textural properties of the designed catalyst were investigated using different characterization techniques to identify suitable catalyst formulation with enhanced catalytic activity and stability. The results demonstrated that WO 3 active species were successfully loaded with uniform distribution onto the support to develop a robust catalyst with both acidic and basic sites. The experimental investigation showed that among the catalysts, WO 3 (10 wt %)/ZnCo 2 O 4 @CeO 2 exhibited the best catalytic activity, providing a maximum levulinic acid yield of 78.49% at the optimal conditions of 6 wt % catalyst dosage, reaction temperature of 180 °C, and reaction time of 200 min. The presence of an optimum number of both acid and base active sites on the catalyst surface could lead to the highest catalytic activity of the synthesized catalyst. Finally, the reusability investigation indicated that the synthesized catalyst possessed sufficient recyclability of up to four times for the levulinic acid production from the selected biomass with negligible drop in the catalytic activity.