Epoxidation of cyclooctene over mesoporous Ga, Ga-Nb, and Ga-Mo oxide catalysts

We demonstrate the epoxidation of cyclooctene to epoxycyclooctane over mesoporous Ga and mixed Ga-Nb and Ga-Mo oxides synthesized via self-assembly hydrothermal-assisted approach. These mesoporous catalysts displayed high epoxide selectivities at moderate cyclooctene conversions. Mesoporous Ga oxides with average particle sizes between 2 and 3 pm exhibited higher cyclooctene conversions, while larger particle sizes between similar to 4.5-6.5 mu m showed lower conversions. The incorporation of Nb led to an increase in the acidity of the resultant Ga-Nb mixed oxides. These mesoporous Ga-Nb mixed oxides displayed 80-100% selectivity for the epoxide at conversion levels of cyclooctene in the 17 to 30% range. Finally, a mesoporous Ga-Mo oxide with molar composition of 35% Mo displayed the highest cyclooctene conversion of all mesoporous samples at 60 degrees C. The conversion of this sample was 41% with 100% selectivity. Published by Elsevier B.V.