Efficient hydrochlorination of glycerol to dichlorohydrin over the COOH-functionalized mesoporous carbon–silica composites

A novel strategy of carbonization and subsequent carboxylation in the confined mesopores of SBA-15 was implemented to synthesize meso-structured carbon/silica(C/Si) composites with enhanced acidity. The XRD and N₂ sorption measurements suggested the preservation of ordered mesoporous structure; FTIR characterization indicated that the C/Sis were successfully modified with –COOH and the acidity of COOH–C/Si material was significantly enhanced. COOH–30C/Si(A) with high COOH density of 2.61 mmol/g and retained mesoporous structure exhibited superior activity for dichlorohydrin production. Through the optimization of reaction variables, as high as 65.7 %, the yield of DCH, can be achieved over COOH–30C/Si(A) after 12 h reaction under 130 °C. Meanwhile, it was 100 % that the conversion of the glycerol can be reached. A significant issue, good durability, especially for practical application, was verified through five consecutive cycles with the optimal reaction variables.