Study of trans-2-hexen-1-ol oxidation over metal-modified mesoporous materials

Abstract

The liquid phase oxidation of trans-2-hexen-1-ol over V-MCM-41 using H2O2 (30 wt.% and 55 wt.%) as oxidant was studied. The V-MCM-41 was synthesized by direct incorporation according to the sol-gel method and characterized by XRD, N2 adsorption-desorption, UV-Vis DR, ICP-OES and FTIR. The high water/oxidant molar ratio in the reaction medium with H2O2 30 wt.% had an adverse effect on the catalytic activity due to the competition between water and oxidant for the active sites of the catalyst. Additionally, a proportional relationship between H2O2 concentration (55 wt.%) and alcohol conversion was observed. However, a decrease in the catalytic activities was found during the recycling tests, indicating the lack of stability of the catalyst under the conditions evaluated. Therefore, 0.1 wt.% of titanium was impregnated on V-MCM-41 and three catalytic cycles were achieved without ignificant loss of activity. In addition, a reaction mechanism was proposed to explain the oxidation products obtained.