Bergwerff Jaap A, van de Water Leon G A, Visser Tom, de Peinder Peter, Leliveld Bob R G, de Jong Krijn P, Weckhuysen Bert M
Department of Inorganic Chemistry and Catalysis, Debye Institute, Utrecht University, The Netherlands.
Chemistry. 2005 Aug 5;11(16):4591-601. doi: 10.1002/chem.200500116.
The physicochemical processes that occur during the preparation of CoMo-Al2O3 hydrodesulfurization catalyst bodies have been investigated. To this end, the distribution of Mo and Co complexes, after impregnation of gamma-Al2O3 pellets with different CoMoP solutions (i.e., solutions containing Co, Mo, and phosphate), was monitored by Raman and UV-visible-NIR microspectroscopy. From the speciation of the different complexes over the catalyst bodies, insight was obtained into the interaction of the different components in the impregnation solution with the Al2O3 surface. It is shown that, after impregnation with a solution containing H2PMo11CoO40(5-), the reaction of phosphate with the Al2O3 leads to the disintegration of this complex. The consecutive independent transport of Co2+ complexes (fast) and Mo6+ complexes (slow) through the pores of the Al2O3 is envisaged. By the addition of extra phosphate and citrate to the impregnation solution, the formation of the desired heteropolyanion can be achieved inside the pellets. Ultimately, the H2PMo11CoO40(5-) distribution could be controlled by varying the aging time applied after impregnation. The power of a combination of spatially resolved spectroscopic techniques to monitor the preparation of supported catalyst bodies is illustrated.
对CoMo-Al₂O₃加氢脱硫催化剂体的制备过程中发生的物理化学过程进行了研究。为此，通过拉曼光谱和紫外-可见-近红外显微光谱监测了用不同的CoMoP溶液（即含有Co、Mo和磷酸盐的溶液）浸渍γ-Al₂O₃颗粒后Mo和Co配合物的分布。从催化剂体上不同配合物的形态，深入了解了浸渍溶液中不同组分与Al₂O₃表面的相互作用。结果表明，用含有H₂PMo₁₁CoO₄₀⁽⁵⁻⁾的溶液浸渍后，磷酸盐与Al₂O₃的反应导致该配合物分解。设想了Co²⁺配合物（快速）和Mo⁶⁺配合物（缓慢）通过Al₂O₃孔的连续独立传输。通过向浸渍溶液中添加额外的磷酸盐和柠檬酸盐，可以在颗粒内部实现所需杂多阴离子的形成。最终，可以通过改变浸渍后施加的老化时间来控制H₂PMo₁₁CoO₄₀⁽⁵⁻⁾的分布。展示了空间分辨光谱技术组合监测负载型催化剂体的制备的能力。
