The identity of titanium centres in microporous aluminophosphates compared with Ti-MCM-41 mesoporous catalyst and titanosilsesquioxane dimer molecular complex: a spectroscopy study
The identity of titanium centres in microporous aluminophosphates compared with Ti-MCM-41 mesoporous catalyst and titanosilsesquioxane dimer molecular complex: a spectroscopy study
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与 Ti-MCM-41 介孔催化剂和钛硅倍半氧烷二聚体分子复合物相比，微孔铝磷酸盐中钛中心的特性：光谱研究
DOI：
10.1016/s1381-1169(03)00330-3
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
L. Marchese
中科院分区：
文献类型：
--
作者：
E. Gianotti;A. Frache;S. Coluccia;John Meurig Thomas;T. Maschmeyer;L. Marchese
以吗啉为结构导向剂，水热合成了具有菱沸石结构的磷酸钛铝和磷酸硅铝（TAPO-34和TAPSO-34）。利用紫外-可见漫反射光谱、光致发光光谱和拉曼光谱研究了这些材料中Ti（IV）位的局域环境。这项研究，结合钛接枝的MCM-41介孔催化剂和钛硅倍半氧烷二聚体分子复合物与一个明确的协调的Ti（IV）中心的研究，揭示了一部分Ti（IV）离子存在于四面体配位，与一些Ti（IV）离子被纳入铝磷酸盐框架一致。然而，拉曼光谱显示，凝胶合成中使用的钛总量的约20%存在于TiO 2样的额外相中。
Titanium-aluminophosphate and silico-aluminophosphate with chabasite-like structures (TAPO-34 and TAPSO-34) have been hydrothermally synthesised using morpholine as structure-directing agent. The local environment of Ti(IV) sites in these materials was studied using diffuse-reflectance UV-Vis, photoluminescence and Raman spectroscopies. This study, combined with the study of Ti-grafted MCM-41 mesoporous catalyst and a titanosilsesquioxane dimer molecular complex with a well-defined co-ordination of the Ti(IV) centers, revealed that a fraction of Ti(IV) ions are present in tetrahedral co-ordination, consistent with some Ti(IV) ions being incorporated into the aluminophosphate frameworks. However, Raman spectroscopy showed that around 20% of the total amount of the titanium used in the gel synthesis is present in a TiO2-like extra-phase.