Characterization of gamma-alumina-supported molybdenum oxide and tungsten oxide : reducibility of the oxidic state versus hydrodesulfurization activity of the sulfided state
Characterization of gamma-alumina-supported molybdenum oxide and tungsten oxide : reducibility of the oxidic state versus hydrodesulfurization activity of the sulfided state
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发表时间：
2003
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通讯作者：
R. Thomas;E. M. V. Oers;V. H. J. D. Beer;J. Medema;J. A. Moulijn
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作者：
R. Thomas;E. M. V. Oers;V. H. J. D. Beer;J. Medema;J. A. Moulijn
使用在大气压下运行的微流反应器，确定了 MOO&-A1203、WOJ-y-A&OS 和 RezO,/y-A&O3 催化剂的噻吩加氢脱硫和丁烯加氢。催化剂的制备方法有离子交换法、气相吸附法、γ-Al2O3干法和湿法浸渍法以及勃姆石浸渍法等。催化剂是在表面覆盖的基础上制备的。通过 X 射线衍射、表面积和孔体积测量以及程序升温还原 (TPR) 对催化剂进行了表征。通过干法和湿法浸渍制备的Moody-Al,O和WO&-A1203催化剂得到基本上相同的结果。通过干法和湿法浸渍制备的氧化型Moody-Al,O和WOJy-A&O3催化剂的还原性与硫化样品的加氢脱硫活性之间存在相关性。还原性越高，加氢脱硫活性越高。这种相关性也适用于通过其他方法（即离子交换、气相吸附和勃姆石浸渍）制备的 Moody-A&O3 催化剂，以及通过干浸渍制备的 Re20,/y-A&O3 催化剂。硫化MoOyly-A12O3和WOJy-Al,OS催化剂的丁烯加氢活性也与还原性相关。这种相关性在性质上与加氢脱硫中发现的相关性相同。对于 Re*O,/y-A12O3 催化剂，情况并非如此。加氢脱硫活性与加氢活性之比按W+MO+Re的顺序降低。 TPR 是一种省时的筛选技术，适用于未推广的分散良好的加氢脱硫催化剂。
Thiophene hydrodesulfurization and butene hydrogenation have been determined for MOO&- A1203, WOJ-y-A&OS, and RezO,/y-A&O3 catalysts, using a micro-flow reactor operating at atmospheric pressure. Catalysts have been prepared by various methods, viz., ion exchange, gas-phase adsorption, dry and wet impregnation of y-Al2O3 as well as impregnation of boehmite. The catalysts have been prepared on a surface coverage basis. The catalysts were characterized by X-ray diffraction, surface area and pore volume measurements, and temperature-programmed reduction (TPR). Moody-Al,O, and WO&-A1203 catalysts prepared by dry and wet impregnation give essentially the same results. A correlation exists between the reducibility of oxidic Moody-Al,O, and WOJy-A&O3 catalysts prepared by dry and wet impregnation, and the hydrodesulfurization activity of the sulfided samples. The higher the reducibility, the higher the hydrodesulfurization activity. This correlation also holds for Moody-A&O3 catalysts prepared by other methods, viz., ion exchange, gas-phase adsorption, and impregnation of boehmite, and for Re20,/y-A&O3 catalysts prepared by dry impregnation. Butene hydrogenation activity of sulfided MoOyly-A1203 and WOJy-Al,OS catalysts also correlates with reducibility. This correlation is qualitatively the same as that found for hydrodesulfuriza-tion. For Re*O,/y-A1203 catalysts this is not the case. The ratio between hydrodesulfurization activity and hydrogenation activity decreases in the order W + MO + Re. TPR is a time-saving screening technique for unpromoted well-dispersed hydrodesulfurization catalysts.