Evidences of the in situ generation of highly active Lewis acid species on Zr-SBA-15

Zr-SBA-15 materials were synthesized and the activity of the catalysts was investigated in the alkylation of aromatics with benzyl chloride. While Zr-SBA-15 materials needed more than 12 h of reaction to achieve quantitative conversion, an unusually high catalytic activity was observed for reused materials that provided quantitative conversions of starting material in less than 1 h. This dramatic increase in activity observed for reused and/or treated Zr-SBA-15 in the alkylation of aromatics with benzyl chloride points to the formation of novel highly acidic Lewis ClxZr–O–Si species on the catalyst surface.

Graphical abstractThe dramatic increase in activity of reused/treated Zr-SBA-15 in the alkylation of aromatics with benzyl chloride points to the formation of novel highly acidic Lewis ClxZr–O–Si species on the catalyst surface. Such materials provided quantitative conversions of starting material in less than 1 h compared to more than 12 h needed for the parent Zr-SBA-15.Figure optionsDownload full-size imageDownload as PowerPoint slide