Hydrodeoxygenation of Guaiacol over Nickel-based Catalyst Supported on Mixed Oxides

Using bimetal mixed oxides Al2O3-SiO2, Al2O3-T1O2, TiO2-SiO2 and TiO2-ZrO2 as supports, nickel catalysts were tested through hydrodeoxygenation ( HDO) reaction of guaiacol and characterized by Brunauer-Emmett-Teller( BET), X-ray diffraction( XRD), NH3 temperature programme desorption( NH3-TPD) and H-2 temperature programme reduction (H-2-TPR) techniques. The effects of support, solvent, reaction temperature and pressure on conversion of guaiacol and selectivity of different products were studied. The resistance of coke, recyclability of catalyst and the reaction mechanism for guaiacol hydrodeoxygenation were also discussed. The results show that the activities of Ni/TiO2-ZrO2 are obviously better than the others under the same reaction conditions. The conversion of guaiacol over Ni/TiO2-ZrO2 catalyst is 100% and the selectivity for cyclohexane is as high as 86.4% under the optimization condition of 300 degrees C and the initial H-2 pressure of 4 MPa in decalin. Moreover, the Ni/TiO2-ZrO(2)catalyst has a better performance of anti-coking than traditional catalysts, about only 3. 2% ( mass fraction) of residual cokes on the catalyst surface.