Enhancing Biomass: Characterization and Application of Rice Husk-Based Catalysts Functionalized with Sn and Mo Oxides for Sustainable Furfural Production

The sustainable production of furfural from biomass-derived sugars is a central challenge in the development of circular chemical processes. In this work, heterogeneous acid catalysts were prepared entirely from rice husk biomass and applied to the dehydration of xylose to furfural. Cellulose extracted from rice husk was converted into mesostructured carbon and functionalized with highly dispersed SnO2 or MoOx nanoparticles, generating bifunctional acidic materials. The combination of well-dispersed tin oxide (SnPTA500) as well as the presence of Lewis acidity enabled furfural yields of up to 78% in a biphasic MIBK/H2O system using concentrated xylose solutions (30 wt %) at 160 °C and 1 h reaction time, while limiting humin formation. The Sn-based catalyst exhibited superior activity, stability, and recyclability. Green metrics analysis revealed clear improvements over state-of-the-art systems, particularly in terms of productivity and material efficiency. Overall, this biomass-derived catalytic platform offers a sustainable and scalable route for furfural production under process-relevant conditions.