Dibenzothiophene hydrodesulfurization over cobalt phosphide catalysts prepared through a new synthetic approach: Effect of the support
Dibenzothiophene hydrodesulfurization over cobalt phosphide catalysts prepared through a new synthetic approach: Effect of the support
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DOI：
10.1016/j.apcatb.2009.07.017
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发表时间：
2009-10-19
影响因子：
22.1
通讯作者：
Jimenez-Lopez, A.
中科院分区：
文献类型：
--
作者：
Cecilia, J. A.;Infantes-Molina, A.;Jimenez-Lopez, A.
通过程序升温还原 (TPR) 负载在不同载体上的亚磷酸氢钴 (II) (Co(HPO3H)(2)) 制备了几种钴负载量为 10 wt% 的磷化钴催化剂：两种介孔载体 MCM-41 和锆掺杂 MCM-41 (MCM-Zr)，以及两种商业载体 SiO2 (Cab-osil) 和 SiO2 (Cab-osil)。 γ-Al2O3。本工作的目的是研究载体对CoP或Co2P形成的作用以及分析二苯并噻吩(DBT)加氢脱硫(HDS)中的催化活性。在给定的实验条件下，这些催化剂最青睐的是 CoP 相，但负载在 γ-Al2O3 (CoP-10 (Al)) 上的催化剂除外，它在还原过程后仅显示 Co2P 相的衍射线。载体-前体盐的相互作用似乎决定了形成哪一相。催化结果表明，该系列催化剂在高温下获得了较高的DBT转化值，主要通过直接脱硫（DDS）路线，即产生联苯（BP）作为主要产物，并达到0.87 x 10(-3) s(-1)的周转频率（TOF）值。运行时间稳定性表明，二氧化硅 (Cab-osil) 负载催化剂 CoP-10 (Cab) 在运行时间 (48 小时) 内高度稳定，转化率接近 100%，性能与 Ni2P 催化剂相似，优于文献报道的其他磷化钴催化剂。相比之下，CoP-10 (Zr) 和 CoP-10 (Si) 样品在运行 16 小时后活性下降，尽管在运行 48 小时后它们的转化率在 65% 至 70% 之间。最后，CoP-10 (Al) 催化剂的转化率较低，并且由于该样品上形成的 Co2P 化合物的活性较低，随着运行时间的推移会发生失活。此外，对废催化剂的分析表明，表面存在硫，这归因于磷硫化物的形成。 (C) 2009 Elsevier B.V. 保留所有权利。
Several cobalt phosphide catalysts, with a cobalt loading of 10 wt%, were prepared by means of temperature-programmed reduction (TPR) of cobalt(II) hydrogenphosphite (Co(HPO3H)(2)) supported on different carriers: two mesoporous supports, MCM-41 and zirconium doped MCM-41 (MCM-Zr), as well as two commercial supports, SiO2 (Cab-osil) and gamma-Al2O3. The purpose of this work is to study the role of the support on the formation of CoP or Co2P and the analysis of the catalytic activity in the hydrodesulfurization (HDS) of dibenzothiophene (DBT). It is the CoP phase which is favoured on these catalysts under the given experimental conditions, except for that supported on gamma-Al2O3 (CoP-10 (Al)), which only displays the diffraction lines of the Co2P phase after the reduction process. The interaction support-precursor salt seems to determine which of the phases is formed. The catalytic results showed that this family of catalysts obtained high DBT conversion values at high temperatures, mainly via the direct desulfurization (DDS) route, i.e., yielding biphenyl (BP) as majority product and attaining turnover frequency (TOF) values of 0.87 x 10(-3) s(-1). The stability with time on stream showed that the silica (Cab-osil) supported catalyst, CoP-10 (Cab), was highly stable with time on stream (48 h) with conversion values close to, 100% and with a performance similar to that of Ni2P catalysts and better than other cobalt phosphide catalysts reported in the literature. In contrast, the CoP-10 (Zr) and CoP-10 (Si) samples decrease in activity after 16 h on stream, although their conversions are between 65% and 70% after 48 h on stream. Finally, the CoP-10 (Al) catalyst provided lower conversion values and underwent deactivation with time on stream due to the low activity of the Co2P compound formed on this sample. Furthermore, the analysis of the spent catalyst showed the presence of sulfur on the surface, assigned to the formation of phosphosulfide species. (C) 2009 Elsevier B.V. All rights reserved.