Liquid phase oxidation of cyclohexane over transition metal incorporated amorphous 3D-mesoporous silicates M-TUD-1 (M = Ti, Fe, Co and Cr)

Redox metals such as Ti, Co, Fe and Cr are incorporated into the framework of TUD-1 (a three-dimensional mesoporous silicate) and characterized by means of XRD, UV–vis and N2 sorption measurements. The catalytic activity of these materials (M-TUD-1) was tested in the liquid phase oxidation of cyclohexane with tert-butylhydroperoxide (TBHP) as oxidant. Cr- and Co-TUD-1 showed excellent performance in the oxidation of cyclohexane, Cr-TUD-1 being highly selective to cyclohexanone. Leaching of Cr is estimated as 13% during this reaction. In contrast to this it was also proven that the reaction is truly heterogeneous with Co-TUD-1.