Interactions of a vinyl ether with acid-modified silica-based catalyst studied by ATR-IR spectroscopy

The interaction of 2-methoxypropene, a vinyl ether, with heterogeneous acid catalysts containing sulfonic acid groups covalently bound to SiO2 (Deloxan ASP, Degussa) and sulfuric acid adsorbed on TiO2-modified amorphous SiO2 (Degussa), respectively, was investigated by in situ attenuated total reflection infrared spectroscopy. Rapid hydrolysis is observed, which does not, however, require the acid sites. The resulting acetone is adsorbed predominantly on SiOH groups. Promoted by the acid sites a further transformation is observed on the catalysts. Based on the time be