Catalytic synthesis of 5-hydroxymethylfurfural from glucose-based carbohydrates via assembled bifunctional SBA-15 mesoporous silica catalysts

Converting glucose-based carbohydrates such as microcrystalline cellulose and cellulose components in lignocellulose into 5-hydroxymethylfurfural (HMF) is a feasible way to achieve high-value utilization of biomass. To this end, this work assembled a series of bifunctional (x)Hf/SBA-15-S catalysts by introducing active hafnium species and grafting sulfonic acid groups onto the mesoporous SBA-15 silica carrier to drive the conversion of glucose, cellulose and untreated wheat straw into HMF. Through detailed parameter evaluation, competitive HMF yields were achieved from glucose (74%) and cellulose (51%), respectively. More importantly, the cellulose and hemicellulose components in untreated wheat straw could be efficiently converted simultaneously to obtain HMF and furfural with yields of 50 and 30%, respectively. Systematic characterization revealed that (x)Hf/SBA-15-S catalysts had an ordered pore channel, bifunctional acidity and good hydrothermal stability, which were beneficial to the process of cellulose undergoing depolymerization, isomerization and dehydration to produce HMF. Therefore, it is believed that the catalytic transformation strategy presented in this study has application prospects for realizing the utilization of glucose-based carbohydrates.