Catalytic activity of an economically sustainable fly-ash-metal-organic-framework composite towards biomass valorization

•A composite has been developed from the MOF, MIL-101 (Cr) and activated fly ash.•The composite dehydrated xylose to furfural with 80.6% selectivity at 150 °C.•The composite has higher hydrothermal stability and Brønsted acidity than bare MOF.•The catalyst synthesis procedures address a way to mitigate the fly ash disposal problems.