Abstract

In the present work, we compared the hydrodesulfurization (HDS) behavior of NiMo catalysts supported on titania-based nanomaterials (hydrogen titanate nanotubes and nanotubes decorated with anatase nanocrystals), with that of the reference NiMo/γ-alumina and NiMo/TiO₂ samples. Supports and calcined catalysts were characterized by nitrogen physisorption, powder XRD, UV–Vis diffuse reflectance spectroscopy, Raman spectroscopy, temperature-programmed reduction, scanning electron microscopy and high resolution transmission electron microscopy (HRTEM). The sulfided catalysts were characterized by HRTEM and evaluated in the HDS of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT). In the hydrodesulfurization of DBT, all catalysts supported on nanostructured titania materials showed similar activity as the NiMo/Al₂O₃ reference. However, their selectivity towards the hydrogenation pathway of the reaction was significantly higher than that of the alumina-supported reference. In the hydrodesulfurization of 4,6-DMDBT, activities of the synthesized NiMo catalysts supported on titania-based nanomaterials were about 50% superior to that of the NiMo/Al₂O₃ reference. This is an interesting result, since the majority of the conventional NiMo or CoMo catalysts are significantly more active for the elimination of DBT than of the sterically-hindered 4,6-DMDBT. The presence of small titania anatase crystallites in the nanostructured supports had a slight positive effect on the catalytic activity of the NiMo catalysts in HDS of 4,6-DMDBT, and a more noticeable effect on an increase in their hydrogenation ability (production of larger amounts of methylcyclohexyltoluene in the products).

Graphic Abstract

中文翻译：

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外来纳米结构的二氧化钛支持深度加氢脱硫催化剂：它们是否比常规催化剂更好？

摘要

在本工作中，我们比较了负载在二氧化钛基纳米材料（钛酸氢纳米管和饰有锐钛矿纳米晶体的纳米管）上的NiMo催化剂的加氢脱硫（HDS）行为，以及参比NiMo /γ-氧化铝和NiMo / TiO ₂的加氢脱硫行为样品。载体和煅烧催化剂的特征在于氮的物理吸附，粉末XRD，UV-Vis漫反射光谱，拉曼光谱，程序升温还原，扫描电子显微镜和高分辨率透射电子显微镜（HRTEM）。通过HRTEM对硫化的催化剂进行表征，并在二苯并噻吩（DBT）和4,6-二甲基二苯并噻吩（4,6-DMDBT）的HDS中进行评估。在DBT的加氢脱硫中，负载在纳米结构二氧化钛材料上的所有催化剂均表现出与NiMo / Al ₂ O ₃相似的活性。参考。然而，它们对反应的氢化途径的选择性显着高于氧化铝负载的参比物。在4,6-DMDBT的加氢脱硫中，负载在二氧化钛基纳米材料上的合成NiMo催化剂的活性比NiMo / Al ₂ O _3的活性高约50％。参考。这是一个令人感兴趣的结果，因为大多数传统的NiMo或CoMo催化剂对消除DBT的活性明显高于对位受阻的4,6-DMDBT。纳米结构载体中存在小的二氧化钛锐钛矿微晶对NiMo催化剂在4,6-DMDBT的HDS中的催化活性有轻微的积极影响，并且对它们的加氢能力增强（产生更多量）有更明显的影响。产品中的甲基环己基甲苯含量）。

图形摘要