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 α-pinene with hydrogen peroxide at 343 K. The catalysts were characterized by N2 adsorption, XRD and DRUV-Vis. The results obtained by varying the Ti content showed slight changes in the α-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.