Ti-MCM-41 as catalyst for α-pinene oxidation -: Study of the effect of Ti content and H2O2 addition on activity and selectivity

Ti containing mesoporous materials with a MCM-41 structure were applied as heterogeneous catalysts for the liquid phase oxidation of alpha-pinene with hydrogen peroxide at 343 K. The catalysts were characterized by N-2 adsorption, XRD and DRUV-Vis. The results obtained by varying the Ti content showed slight changes in the alpha-pinene conversion. The major products were verbenol, verbenone and campholenic aldehyde with a conversion about 12-16%. The yield of the reaction products was duplicated when an additional amount of H2O2 was added after 1 h of reaction. A high selectivity was obtained for the products of the allylic oxidation. A reaction mechanism was proposed in order to explain the obtained results. (C) 2007 Elsevier B.V. All rights reserved.