Propylsulfonic acid and methyl bifunctionalized TiSBA-15 silica as an efficient heterogeneous acid catalyst for esterification and transesterification

• Published in: Microporous and mesoporous materials 2015-03, Vol.204, p.218-225
• Main Authors: Léon, Camara Ibrahima Sory, Song, Daiyu, Su, Fang, An, Sai, Liu, Hongbo, Gao, Jie, Guo, Yihang, Leng, Jiyan
• Format: Article
• Language: English
• Subjects: Biodiesel; Inedible oily feedstocks; Ordered mesoporous silica; Organosulfonic acid; Solid acid
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2014.11.018

[Display omitted] •Propylsulfonic acid and methyl bifunctionalized TiSBA-15 material are prepared.•As prepared TiSBA-15-Me-PrSO3H exhibits excellent catalytic activity in biodiesel production.•Enhanced total acidity and surface hydrophobicity contribute to excellent catalytic activity.•The TiSBA-15-Me-PrSO3H can be reused at least 3 times without loss of the activity. Propylsulfonic acid and methyl bifunctionalized TiSBA-15 silica material, TiSBA-15-Me-PrSO3H, is prepared by a direct nonionic surfactant-templated sol–gel co-condensation approach combined with low-temperature hydrothermal treatment. The structural integrity of the incorporated propylsulfonic acid groups and terminally bonding methyl groups are studied by 13C CP-MAS NMR and 29Si MAS NMR spectroscopy, while the chemical state of Ti(IV) species in the hybrid material is tested by XPS and UV–Vis/DRS. The ordered mesostructure, morphology and porosity of as-prepared hybrid material are characterized by low-angle XRD measurements, TEM observations and nitrogen gas porosimetry measurements. As the efficient solid acid catalyst, the heterogeneous acid catalytic activity and stability of the TiSBA-15-Me-PrSO3H are evaluated by esterification of palmitic acid and transesterification of yellow horn oil with methanol under refluxing temperature (65°C) and atmospheric pressure. Based on the physicochemical properties and catalytic testing results, the excellent heterogeneous acid catalytic behaviors of as-prepared hybrid catalyst are explained by the contribution of their strong Brönsted and Lewis acidity, excellent porosity properties as well as surface hydrophobicity.