Synthesis of solketal from glycerol over modified SiO2 supported p-phenolsulfonic acid catalyst

Acetalization of glycerol with acetone could convert surplus glycerol into an important fuel additive (solketal). In this work, a stable solid acid catalyst was synthesized in a facile polycondensation of p -phenolsulfonic acid on KH560 modified SiO 2 (PSF/K-SiO 2 ) and used in the acetalization of glycerol at room temperature. Characterization results confirmed that PSF/K-SiO 2 possessed larger surface area and surface acidity than that of PSF resin (copolymer of p -phenolsulfonic acid and formaldehyde) and non-modified SiO 2 supported PSF resin (PSF/SiO 2 ). As a result, PSF/K-SiO 2 was extremely active and stable in the acetalization of glycerol. At 25 °C, the detected conversion of glycerol reached 86.3% with a 97.7% selectivity of solketal at 1.5 h. The best yield of solketal over PSF/K-SiO 2 could reach 93.1 g-solketal/g-cat/h, and PSF/K-SiO 2 could be recycled at least 5 times without obvious decrease in reactivity.