Co-Mo/Al2O3加氢脱硫催化剂的CO吸附原位红外光谱表征及应用研究

燃油的无硫化成为车用燃料发展的必然趋势.为开发高性能的柴油超深度加氢脱硫催化剂,文章采用CO吸附原位红外光谱法对系列还原态Co-Mo/Al2O3催化剂和高活性工业剂进行了表征,并将表征结果与微反加氢脱硫活性评价结果进行了关联分析.结果表明:随金属负载量的变化CO吸附的光谱特征发生变化,当MoO3负载量达20%、助剂CoO量为4.16%时,在2 179 cm-1出现一个新的CO特征吸收峰,该活性中心的出现明显有利于加氢脱硫(HYD)的反应.在相同金属负载量的情况下,与采用化学处理法制备的催化剂相比较,后者对应的2179 cm-1的特征吸收明显增强,微反评价显示该催化剂的催化活性特别是HYD反应活性明显提高.

In-situ FTIR Study of CO Adsorption on Co-Mo/Al2O3 Hydrodesulphurization Catalysts

Due to the implementation of more stringent specifications in sulfur content for diesel oil, a deep understanding of the active phase of Co-Mo/Al2O3 catalysts is necessary to the development of ultra-deep hydrodesulphurization (HYD) catalysts. A series of reductive Co-Mo/Al2O3 catalysts prepared in the lab and the high-active industrial catalyst (G) were studied by in-situ FTIR using CO as probe molecule. The showed a good relationship with the desulphurization activities of the catalysts. With the increase in MoO3 and CoO loading, the desulphurization activity of catalyst increases, and the infrared spectrum changes with the amount of CO adsorbed on the catalyst. There is a new band at 2 179 cm-1 when the MoO3 loading is up to 20% and CoO up to 4.16%. According to the activities of the catalysts, the appearance of this new band suggests that the catalyst has higher hydrodesulphurization (HYD) activity. Compared with the infrared spectrum of CO on the catalyst of the same MoO3 and CoO loading by the common preparation method, the catalyst prepared with chelating agents has higher HYD activity and its band at 2 179 cm-1 is stronger. The infrared spectrum of CO adsorbed on optimum Co-Mo/Al2O3 catalyst prepared in the lab is similar to the highly active industrial catalyst (G). Their bands at 2 179 cm-1 are both very strong and their HYD activities are both higher than the others. Thus, the appearance and the increase of the band at 2 179 cm-1 indicate the increase in the HYD activity of Co-Mo/Al2O3 catalysts to some extent, which could be an effective tool for developing ultra-deep HYD catalysts.