Sorbitol dehydration into isosorbide over a cellulose-derived solid acid catalyst

The dehydration of sorbitol to isosorbide over an environmentally benign cellulose-derived solid acid catalyst (CCS) has been investigated in order to develop a sustainable process for isosorbide production. The as-prepared CCS sample contained large amounts of -COOH, phenolic hydroxyl and -SO3H groups and presented satisfactory catalytic activity, isosorbide selectivity and recyclability under water-free conditions. Various methods such as BET, XPS, TG, SEM, FT-IR and pyridine adsorption were conducted to characterize the CCS catalyst in order to elucidate the possible catalyst structure-performance relationship. The results of FT-IR and pyridine adsorption revealed that most of the acid sites contained in CCS catalyst were assigned as strong Bronsted sites, which were crucial for catalytic sorbitol dehydration into isosorbide. When further compared to the conventional solid acid catalyst (niobic acid), the investigated CCS catalyst in this study was considered as one of the promising alternatives to the highly efficient catalysts for isosorbide production from sorbitol.