| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 55616 | Catalysis Today | 2012 | 7 Pages |
Zeolites differing in structure and acidity were tested in liquid phase acylation of p-xylene. Hexanoyl chloride, propionic anhydride and isobutyric anhydride were used as acylating agents. The highest conversions of acylating agent were achieved over large pore zeolites USY (66.3%) and Beta (58.2%). It was found that acylation of p-xylene proceeds only over large pore zeolites Beta and USY. Selectivities to monoacylated p-xylene obtained over USY zeolite decreased in the order: propionic anhydride 78.0% > hexanoyl chloride 67.2% > isobutyric anhydride 33.1%. Diacylated product was formed over zeolite USY with all acylating agents tested but only with hexanoyl chloride over zeolite Beta. It was found that the optimum Si/Al ratio of zeolite Beta for p-xylene acylation with propionic anhydride is 25, while for isobutyric anhydride is 19. Conversion of isobutyric anhydride decreased with increasing isobutyric anhydride concentration and increased with increasing amount of catalyst.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (104 K)Download as PowerPoint slideHighlights► The acylation of p-xylene with acid anhydrides and acyl chlorides over different structural types of zeolites was studied. ► The effect of the catalyst structure, its acidity and type of acylating agent on the conversion and selectivity in p-xylene acylation was tested. ► The effect of amount of the catalyst, the molar ratio acylating agent/substrate on the course of the reaction were investigated.
