Phosphotungstic acid functionalized biochar for furfural production from corncob

Upgradation of lignocellulosic biomass to valuable chemicals has regarded as an effective way for the utilization of renewable carbon sources. Furfural is one of the important chemicals derived from biomass. However, the two-step preparation of sulfonated solid acid for furfural production is complicated. It is necessary to discover a simple one-step solid acid preparation for industrial applications. In this study, the phosphotungstic acid functionalized biochar (PA-FCB) were synthesized by the hydrothermal treatment of microcrystalline cellulose and phosphotungstic acid in one step for valorization of corncob to furfural. The catalytic performance of PA-FCB in γ-valerolactone/water solvent was evaluated, and a furfural yield of 96.06% was observed at 468 K for 120 min. The results indicate that PA-FCB exhibit excellent catalytic performance for the transformation of corncob to furfural. As the Py-FTIR and XPS of PA-FCB demonstrated, PA-FCB contained both Brønsted acid sites (carboxyl groups) and Lewis acid sites (caused by CC bonds and hydroxyl groups), which result in the high catalytic activity. Additionally, the kinetics for the PA-FCB catalyzed furfural production were systematically studied, which could provide a prediction of the overall catalytic system. The present paper gave an effective and comprehensive production strategy for furfural from lignocellulosic biomass.