Epoxidation of styrene with molecular O2 over sulfated Y–ZrO2 based solid catalysts

Liquid phase epoxidation of styrene was studied over non-sulfated and sulfated yttria–zirconia (Y–ZrO2) based solid catalysts using molecular O2 in the presence of DMF solvent. All catalysts yielded styrene oxide and benzaldehyde as two major products. Among all the catalysts studied, sulfated Co–Y–ZrO2 catalyst resulted in the maximum (61%) styrene conversion with 80% styrene oxide selectivity. Reactions studied in the absence of DMF solvent or in the presence of a small amount of water favored benzaldehyde formation predominantly. Thermally regenerated catalysts showed slight lower conversion (54%) without affecting the selectivity through three reaction cycles.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (53 K)Download as PowerPoint slideResearch highlights▶ Sulfated catalysts showed enhanced activity values than non-sulfated catalysts. ▶ DMF solvent favored the formation of styrene oxide. ▶ In the absence of DMF solvent benzaldehyde formation predominantly occurred. ▶ Sulfated Co–Y–ZrO2 showed maximum styrene conversion of 61% with 80% styrene oxide.