Microwave-assisted coating of carbon nanostructures with titanium dioxide for the catalytic dehydration of d-xylose into furfural

Abstract

Titanium dioxide was selectively grown on reduced graphene oxide (TiO₂/RGO) and carbon black (TiO₂/CB) by a microwave-assisted synthesis in benzyl alcohol to produce nanocomposite catalysts (consisting of 8–9 nm anatase nanoparticles dispersed on the carbon surface) with interesting properties for the production of furfural from renewable carbohydrate biomass. The materials efficiently catalyze the aqueous-phase dehydration of xylose into furfural at 170 °C with high furfural yields (67–69%) at high conversions (95–97%). The catalytic performance was not significantly affected by the type of carbon support, suggesting that cheap amorphous carbons can be used to support the titania nanoparticles. Additionally, the catalysts were found to be stable under hydrothermal conditions and outstandingly stable towards coke formation in comparison to other solid acid catalysts reported in the literature. Both composites were reused after a simple wash and drying procedure without any detectable loss of catalytic activity in consecutive batch runs.