Binary oxide nanofiber bundle supported Keggin-type phosphotungstic acid for the synthesis of 5-hydroxymethylfurfural

A novel hierarchically fibrous solid acid catalyst was facilely prepared by supporting Keggin-type phosphotungstic acid (HPW) on fibrous substrate of mesoporous TiO2-Al2O3 binary oxide nanofiber bundles. The acid strength and specific surface area were rationally tuned by changing the composition of TiO2-Al2O3 nanofiber bundles. When applied in fructose dehydration to prepare 5-hydroxymethylfurfural (5-HMF) using DMSO as the solvent, the fibrous HPW/TiO2-Al2O3 catalyst exhibited high catalytic activity (80.3%), selectivity (89.3%) and stability during the cycles. Our results demonstrated a promising and facile strategy for developing highly active and recyclable solid acid catalysts.