CoMo/Al2O3 catalysts prepared on the basis of Co2Mo10-heteropolyacid and cobalt citrate: Effect of Co/Mo ratio
CoMo/Al2O3 catalysts prepared on the basis of Co2Mo10-heteropolyacid and cobalt citrate: Effect of Co/Mo ratio
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DOI：
10.1016/j.fuel.2011.11.028
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发表时间：
2012-10
期刊：
影响因子：
7.4
通讯作者：
P. A. Nikul’shin;A. Mozhaev;A. Pimerzin;V. Konovalov;A. Pimerzin
中科院分区：
文献类型：
--
作者：
P. A. Nikul’shin;A. Mozhaev;A. Pimerzin;V. Konovalov;A. Pimerzin
考察了Co/Mo比对同时使用十钼二钴杂多酸（杂多酸10 HPA）和柠檬酸钴制备的CoMo/Al 2 O3加氢处理催化剂的影响。采用拉曼光谱、N2吸附、XRD、XPS、HRTEM等技术对催化剂进行了表征，并在4，6-二甲基二苯并噻吩（4，6-DMDBT）加氢脱硫模型反应、直馏柴油（SRGO）加氢处理和80 vol.%（质量分数）柴油混合物加氢处理中进行了考察含20 vol.%的SRGO轻焦化瓦斯油（LCGO）。结果表明，催化剂中Co/Mo比对CoMoS II型相的结构和催化活性有显著影响。当λ=Co/（Co+Mo）=0.35时，催化剂在4，6-DMDBT加氢脱硫和柴油HDT中的活性最高，稳定性最好。随着Co/Mo比的增加，CoMoS多层活性相的平均长度和堆积数同时增加。平均长度从3.0增加到4.0nm，平均桩数从1.4增加到1.6。发现Co/Mo比λ在0.35 ~ 0.45范围内，催化剂活性降低。通过对催化剂的结构、活性相形态、相组成和催化活性的分析，推测随着Co/Mo比的增加，活性组分的硫化物和焦炭物质会堵塞中孔，形成新的微孔。结果表明，制备的CoMo/Al 2 O3催化剂对SRGO或SRGO与LCGO的混合物的加氢处理活性可与工业超低硫柴油催化剂相媲美。
The effect of Co/Mo ratio in the CoMo/Al2O3hydrotreating catalysts prepared by simultaneous using of the decamolybdodicobaltate heteropolyacid (Со2Мо10HPA) and cobalt citrate was investigated. Synthesized catalysts were characterized by Raman spectroscopy, N2adsorption, XRD, XPS, HRTEM techniques and were examined in the model reaction of 4,6-dimethyldibenzothiophene (4,6-DMDBT) HDS, in hydrotreating of straight-run gas oil (SRGO) and mixture of 80vol.% SRGO with 20vol.% light coker gas oil (LCGO). It was established that Co/Mo ratio in the catalysts significantly influences on the structure of CoMoS phase of type II and catalytic activity. Catalysts with λ=Co/(Co+Mo)=0.35 had maximal activities in 4,6-DMDBT HDS and diesel HDT and showed the best stability. Increase of the Co/Mo ratio led to simultaneous growing of both average length and stacking number of CoMoS multilayer active phase of the catalysts. Average length increased from 3.0 to 4.0nm, average staking number increased from 1.4 to 1.6. It was found out that catalysts activity decreased within Co/Mo ratio λ from 0.35 to 0.45. Analysis of textural properties of the catalysts, active phase morphology, phase composition and catalytic activities allowed us to suppose that with increase of Co/Mo ratio blocking the mesopores by sulfides of the active components and by coke species with formation of new micropores would take place. The activity of the best prepared CoMo/Al2O3catalyst was competitive with the activity of the well-known commercial catalysts for ultra-low sulfur diesel in hydrotreating of SRGO or mixture of SRGO with LCGO.