高表面积复合氧化物Co-O-Si的制备及其催化1-己烯骨架异构和噻吩加氢脱硫活性

摘要

通过硝酸钴与硅酸钠共沉淀、辅以正丁醇干燥技术制备了具有原子分散度的Co-O-Si复合氧化物(Co/Si原子比≈0.65),该催化剂具有较大的比表面积(562 m2/g)和较强表面酸性.在硫化处理后,能够形成高度分散的硫化物活性组分,在模型汽油加氢处理反应中显示了较高的催化活性,在573 K时,噻吩的加氢脱硫活性可达99.4%,同时,1-己烯的骨架异构收率达到了35%.该催化剂虽然不含Mo,其加氢脱硫活性可与工业催化剂Co-Mo/γ-Al2O3相当.而在汽油深度加氢脱硫过程中,直链烯烃往往被加氢饱和,造成辛烷值损失.该催化剂则可使部分直链烯烃发生骨架异构而生成异构烷烃,可减少深度加氢脱硫过程中的辛烷值损失.%The coprecipitation of sodium silicate with cobalt nitrate, combined with an n-butanol drying pro-cess, led to the formation of a Co-O-Si complex oxide (Co/Si atomic ratio≈0.65) with atomically dispersed Co and Si atoms. The complex oxide had a high surface area (562 m2/g) and strong sur-face acidity. Sulfidation resulted in the formation of highly dispersed cobalt sulfide, which had high activity in the hydrodesulfurization (HDS) of thiophene (99.4%) and skeletal isomerization of 1-hexene (35%) at 573 K. The HDS activity was as high as that of the industrial catalyst Co-Mo/γ-Al2O3, although no Mo was present. The material could therefore be used for the skeletal isomerization of linear olefins during deep HDS of gasoline to reduce octane number loss caused by olefin saturation.