Al_2o_3-tio_2/al_2o_3-tio_2-sio_2 Composite-supported Bimetallicpt-pd Catalysts For The Hydrodearomatization And hydrodesulfurization Of Diesel Fuel

摘要

Al_2O_3-TiO_2 and Al_2O_3-TiO_2-SiO_2 (denoted as AT and ATS) composite oxides were synthesized by the sol-gel method, which were used as supports for bimetallic Pt-Pd catalysts. The typical physicochemical properties of the catalyst samples were characterized by means of N_2 adsorption, UV-vis diffuse reflectance spectroscopy (DRS), and X-ray diffraction (XRD). The diesel hydrodearomatization (HDA) and hydrodesulfurization (HDS) activities of the catalysts were evaluated using a microreactor system. In comparison to the Pt-Pd/AT catalysts, all of the Pt-Pd/ATS catalysts showed much higher HDA activities. A 100 h test showed that the Pt-Pd/ATS catalyst had a high equilibrium HDA activity, with 432 ppm sulfur diesel. The enhanced HDA activity and sulfur tolerance of Pt-Pd/ATS were likely attributed to the incorporations of Ti and Si into Al_2O_3, which optimized the interaction between the catalyst support and active metals.