Herein, we present the aerosol-assisted sol–gel preparation of hierarchically porous TiO₂–SiO₂ catalysts having a spherelike shell morphology and a high Ti dispersion. In order to control the porosity at the micro-, meso-, and macrolevels, we use the evaporation-induced self-assembly (EISA) of a surfactant, possibly combined with polymer beads as hard templates. These catalysts are tested for the epoxidation of cyclohexene with cumene hydroperoxide as the oxidant, and their performance is compared to the reference TS-1 zeolite. The high catalytic performance observed with the catalysts prepared by aerosol stems from their high specific surface area, but also from the short diffusion path length generated by the meso-/macropore architecture which provides entryways for bulky reactants and products. Besides, these materials can incorporate a higher Ti loading than TS-1 zeolite, while ensuring a good control over the Ti speciation. Thus, the unique features of the aerosol process—which is also known to be scalable—allow us to prepare catalytic materials with high epoxidation activity, also for bulky olefins.

中文翻译：

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具有气孔结构和高环氧化活性的TiO ₂ -SiO ₂催化剂的气溶胶路线

在这里，我们介绍了分层多孔TiO ₂ -SiO ₂的气溶胶辅助溶胶-凝胶制备具有球形壳形态和高Ti分散度的催化剂。为了控制微观，中观和宏观水平的孔隙率，我们使用了表面活性剂的蒸发诱导自组装（EISA），可能与聚合物珠粒结合使用作为硬模板。测试了这些催化剂的环己烯与异丙苯氢过氧化物作为氧化剂的环氧化，并将其性能与参考TS-1沸石进行了比较。用气溶胶制备的催化剂观察到的高催化性能源于它们的高比表面积，还源于中/大孔结构所产生的短扩散路径长度，该结构为庞大的反应物和产物提供了入口。此外，这些材料可掺入比TS-1沸石更高的Ti含量，同时确保对Ti形态的良好控制。因此，