Solvent-Free Liquid Phase Oxidation of Benzyl Alcohol to Benzaldehyde over Superfine MgAl2O4 Supported Co-Based Catalysts：Effects of Support MgAl2O4

MgAl2O4 was respectively prepared by hydrothermal method (MgAl2O4-HT), co-precipitation method (MgAl2O4-CP) and solid reaction method (MgAl2O4-SR). The as-synthesized MgAl2O4 was used as support to prepare CoOx/MgAl2O4 catalysts for the liquid phase oxidation of benzyl alcohol to benzaldehyde by H2O2. The catalytic performance and properties of these supports and catalysts were comparatively investigated by catalytic test, XRD, XRF, N2 isothermal adsorption-desorption, TEM and H2-TPR technologies. The properties of support MgAl2O4 was strongly depended on the preparation method of the support, which affected the catalytic activity of CoOx/MgAl2O4 catalysts in the reaction. CoOx/MgAl2O4-HT exhibited the higher catalytic reactivity and better reusability than CoOx/MgAl2O4-CP and CoOx/MgAl2O4-SR in the reaction, because MgAl2O4-HT was high-surface-area porous nanometer spinel MgAl2O4.