1-Butanol etherification over sulfonated mesostructured silica and organo-silica

A new series of sulfonated mesoporous silica and organosilica was synthesized and their catalytic activity was investigated in 1-butanol dehydration reaction. The reaction was carried out in liquid phase inside a batch reactor equipped with a diamond FTIR probe for continuous concentration monitoring of 1-butanol and reaction products namely dibutyl ether (DBE) and water. Good catalytic activity and high conversion from 1-butanol to DBE was observed for all catalysts which include sulfonic acid functionalized SBA-15 (SAF-SBA-15), arenesulfonic acid functionalized SBA-15 (ArSAF-SBA-15) and arenesulfonic acid functionalized mesostructured ethane silica (ArSAF-MES). ArSAF-MES showed the highest 1-butanol conversion (≈80%) at 473 K compared to all other catalysts tested. A kinetic model was adopted for this reaction that describes the strong competition effect between water and alcohol molecules for -SO3H active sites. The higher catalytic activity of ArSAF-MES is associated with the more hydrophobic nature of -SO3H environment in this material.