| As the potential for replacing fossil fuel, bio-oil’s source was very broad and it was a very important renewable energy. It had low sulfur content and zero net emission of CO2 after burning. So if it could be directly converted to liquid fuels, it can be used to protect the environment, to optimiz energy structure and to recycle the energy.In this paper, the aqueous solution of phenol was a simulation of bio-oil, we investigated aqueous-phase hydrodeoxygenation (HDO) of phenol over the supported Pd catalysts in the fixed bed reactor. We used different supports and modified the supports to synthesize a series of supported noble catalysts. In the process, we used N2 physical adsorption, XRD and NH3-TPD to characterize the catalysts. Finally the purpose of HDO of phenol was achieved by optimizing reaction conditions and modifying the supports.We found that the supports’acids had a great influence on the activity of HDO by the research of aqueous HDO of phenol over the supported Pd catalysts. In the selected four supports, Hβ has more acids, and the activity of Pd/Hβ was better. The order of activities was: Pd/Hp> Pd/Al2O3> Pd/HMCM-41> Pd/SiO2. Ce-β and Pd/Ce-β were prepared by an incipient impregnation method, and characterized by means of XRD, N2 adsorption, NH3-TPD. It was shown that Ce existed in the form of CeO2 and the specific surface area of Hβ zeolite decreased after the preparation while the dispersion of Pd was raised. The aqueous-phase HDO performances of the prepared catalysts were investigated using a model fuel containing 5.0 wt.% phenol in the water. It was found that Pd/Ce-β showed higher HDO activity than Pd/Hβ, enhancing the hydrogenation activity. The strong acidity decreased when the content of Ce was 10 wt.% and the deoxidizing activity was inhibited. |
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