MCM-48 as a support for sulfonic acid catalysts

The ordered mesoporous silica, MCM-48, has been functionalised with sulfonic acid. Its physico-chemical properties have been compared with those of sulfonated MCM-41 and SBA-15. A higher catalytic activity for the functionalised MCM-48 in the alkylation of toluene with benzyl alcohol suggests that MCM-48 behaves as a better sulfonic acid support than MCM-41 and SBA-15. Ammonia adsorption calorimetric data shows that acid site strengths on the three supports are similar so the higher activity of MCM-48 sulfonic acid is probably due to better accessibility of its acid sites in the three-dimensional pore structure.