Highly selective mono-epoxidation of dicyclopentadiene with aqueous H2O2 over heterogeneous peroxo-phosphotungstic catalysts

Anionic resin supported peroxo phosphotungstic acid catalysts with different contents of peroxo phosphotungstic acid are prepared through a simple anion-exchange from spherical chloride-form resin pre-treated with organic amine. Thus-prepared materials possess typical Keggin structures, irregular morphologies, high metal content, as revealed by XRD, SEM, TEM, EDX, and IR. UV-vis, Raman and XPS spectra prove the formation of peroxo phosphotungstic acid in high dispersion on the resin. Among these solid catalysts, chloromethylated polystyrene resin-supported peroxo phosphotungstic acid (PSC-3) exhibits the best activity for the titled reaction to obtain 91.8 mol% conversion of dicyclopentadiene and 90.0% selectivity of mono-epoxide. PSC-3 catalyst behaves as a truly heterogeneous catalyst that can be reused nine times without any loss of activity. Some factors play important roles in controlling the mono-epoxidation. (C) 2016 Elsevier B.V. All rights reserved.