摘要
本文研究了硼的加入对 Ni- Mo/ γ- Al2 O3 催化剂的结构和催化活性的影响及超稳定 Y型沸石 USY(ultra-stable Y- type zeolite)为载体的新型 Ni- Mo环境催化剂。硼的加入改变了酸点的酸度和催化剂活动金属的分散性 ,因而提高了这些模型化合物在 Ni- Mo/γ- Al2 O3 催化剂作用下的活性。
Catalytic hydrogenation and hydrocracking (HC) are used in the process of refining of petroleum and liquefied coal. The most popular catalysts used in industry are Co-and-Ni-promoted Mo and W sulfide supported on γ-Al 2O 3. New generation of catalysts is in great demand since the international rules require that the contents of pollutants such as S, N and poisonous heavy metals contained in oil in industrialized countries must be reduced to one tenth of the present level.For such purpose,the effects of boron B on the structure and activity of Ni-Mo/γ-Al 2O 3 catalysts are studied in the present paper. The γ-Al 2O 3-B 2O 3 supports and Ni-Mo/γ-Al 2O 3-B 2O 3 catalysts in which the contents of NiO and MoO 3 are 3% and 12% respectively are prepared by impregnation method. Diphenyl and cyclohexylbenzene are derived after drying, calcination and sulfuration of these catalysts and the hydrodesulfurization (HDS) of dibenzothiophene (DBT). The contents of the components are analyzed by gas chromatography and the relation between B and activity is presented (Fig.1A). X-ray diffraction and X-ray photo-electron spectrum are used to analyze the surface acidity and dispersion of metals. It is shown that the addition of B modifies the acidity of the acid sites and the active metal dispersion of the catalysts and thus enhances the catalytic hydroprocessing activities of these model compounds over the Ni-Mo/γ-Al 2O 3 catalysts. Activity achieves the maximum value when the content of B 2O 3 is 1%.Ultrastable Y-type (USY) zeolite supported Ni-Mo environmental catalysts are also studied. NH 4-Y-type zeolite is gained by using Na-Y-type zeolite and through ion exchange of (NH 4) 2SO 4. USY-type zeolite is obtained after the calcination of NH 4-Y-type zeolite, dealuminufication and removing Al by H 2SO 4. Catalysts supported on USY-type zeolite are prepared by ion exchange method. These catalysts are decarbolized by H 2S-H 2 at 400 ℃ and applied to HDS reaction of DBT and HC reaction of decalin, diphenylmethan and tetralin. USY-type zeolite-supported Ni-Mo environmental catalyst has significantly higher activity than other zeolites and these zeolites-supported Ni-Mo catalysts. In fact, USY-zeolite-supported Ni-Mo catalyst has much higher HC and HDS activity than Al 2O 3-supported Ni-Mo catalyst.
出处
《安全与环境学报》
CAS
CSCD
2001年第2期42-44,共3页
Journal of Safety and Environment
