Segura Y, Cool P, Kustrowski P, Chmielarz L, Dziembaj R, Vansant E F
Department of Chemistry, Laboratory of Adsorption and Catalysis, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
J Phys Chem B. 2005 Jun 23;109(24):12071-9. doi: 10.1021/jp0507750.
Supported vanadium and titanium oxide catalysts were prepared by adsorption and subsequent calcination of the vanadyl and titanyl acetylacetonate complexes, respectively, on mesoporous SBA-15 by the molecular designed dispersion (MDD) method. Liquid and gas phase depositions at different temperatures were carried out with vanadyl acetylacetonate, and the different results together with those of titanyl acetylacetonate in the liquid phase deposition were discussed. The bonding mechanism, the influence of the metal interaction with the support material, and differences due to the way of deposition and the temperature were investigated by TGA, chemical analysis, FTIR, and Raman spectroscopy. Elevated dissolving temperatures in the liquid phase led to higher final loadings on the SBA-15 without the formation of clusters, even at high loadings. The decomposition of the anchored vanadium and titanium complexes, their thermal stability, and the conversion to the covalently bound VO(x) and TiO(x) species on SBA-15 were studied and investigated by in situ transmission IR spectroscopy. In general, the titanium complex is more reactive than the vanadium complex toward the surface of SBA-15 and has a higher thermal stability. The MDD method of the VO(acac)2 and TiO(acac)2 enables to create a dispersed surface of supported VO(x) and TiO(x), respectively. The structure configurations of VO(x) and TiO(x) oxide catalysts obtained at different metal loadings were studied by Raman spectroscopy. Pore size distributions, XRD, and N2 sorption confirmed the structural stability of these materials after grafting. VO(x)/SBA-15 and TiO(x)/SBA-15 samples, with different metal loadings, were also catalytically tested for the selective catalytic reduction (SCR) of NO with ammonia.
通过分子设计分散（MDD）方法，分别将乙酰丙酮氧钒和乙酰丙酮氧钛配合物吸附在介孔SBA-15上，随后进行煅烧，制备了负载型钒和钛氧化物催化剂。用乙酰丙酮氧钒在不同温度下进行液相和气相沉积，并讨论了不同的结果以及液相沉积中乙酰丙酮氧钛的结果。通过热重分析（TGA）、化学分析、傅里叶变换红外光谱（FTIR）和拉曼光谱研究了键合机理、金属与载体材料相互作用的影响以及由于沉积方式和温度导致的差异。即使在高负载量下，液相中溶解温度的升高也会导致SBA-15上的最终负载量更高，且不会形成团簇。通过原位透射红外光谱研究了SBA-15上锚定的钒和钛配合物的分解、它们的热稳定性以及向共价键合的VO(x)和TiO(x)物种的转化。一般来说，钛配合物对SBA-15表面的反应性比钒配合物更高，且具有更高的热稳定性。VO(acac)2和TiO(acac)2的MDD方法分别能够创建负载型VO(x)和TiO(x)的分散表面。通过拉曼光谱研究了在不同金属负载量下获得的VO(x)和TiO(x)氧化物催化剂的结构构型。孔径分布、X射线衍射（XRD）和N2吸附证实了接枝后这些材料的结构稳定性。还对不同金属负载量的VO(x)/SBA-15和TiO(x)/SBA-15样品进行了氨选择性催化还原（SCR）NO的催化测试。
