Metal–organic frameworks (MOFs) and related derivatives have attracted significant research attention due to their potential applications in a variety of fields. However, it remains challenging to fabricate MOF‐based composites into multidimensional structures, especially to endow them with ordered structures. Here, a facile strategy is developed for the preparation of Pt@ zeolitic imidazolate frameworks (ZIF)‐8/SiO₂ composite with 3D‐ordered macroporous (3DOM) structure (denoted as 3DOM‐Pt@ZIF‐8/SiO₂) by the in situ self‐templated transformation of Pt/ZnO/SiO₂ composite with 3DOM structure (denoted as 3DOM‐Pt/ZnO/SiO₂), which is prepared by a nanocasting method with face‐centered cubic (fcc) polystyrene spheres as the template. The sampling analysis at various crystallization times confirms the detailed dissolution–precipitation process from 3DOM‐Pt/ZnO/SiO₂ to 3DOM‐Pt@ZIF‐8/SiO₂, in which Pt nanoparticles (NPs) are fully encapsulated into the 3DOM framework of ZIF‐8/SiO₂ by a continuous ZIF‐8 shell in the surface. Besides, it is found that choosing suitable volume ratio of N,N‐dimethylformamide (DMF):H₂O and SiO₂ content is crucial to induce the in situ nucleation and growth of continuous ZIF‐8 shell on the 3DOM structure and also to prevent the 3DOM structure from collapsing. Crucially, the obtained 3DOM‐Pt@ZIF‐8/SiO₂ shows high size‐selective catalytic properties for the hydrogenation of n‐hexene and cis‐cyclooctene due to the molecular sieve effect of ZIF‐8 shell on the framework.

中文翻译：

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具有3D顺序大孔和尺寸选择性催化性能的Pt @ ZIF-8 / SiO2复合材料的自模板形成

金属有机骨架（MOFs）及其相关衍生物由于其在各个领域的潜在应用而引起了广泛的研究关注。但是，将基于MOF的复合材料制成多维结构仍然是一项挑战，尤其是要赋予它们有序的结构。在这里，开发了一种简便的策略来制备具有3D顺序大孔（3DOM）结构（表示为3DOM-Pt @ ZIF-8 / SiO ₂）的Pt @沸石咪唑酸酯骨架（ZIF）-8 / SiO ₂复合材料。具有3DOM结构的Pt / ZnO / SiO ₂复合材料的原位自模板转变（表示为3DOM-Pt / ZnO / SiO ₂），它是通过纳米浇铸法制备的，以面心立方（fcc）聚苯乙烯球为模板。在不同结晶时间的采样分析证实了从3DOM-Pt / ZnO / SiO ₂到3DOM-Pt @ ZIF-8 / SiO ₂的详细溶解-沉淀过程，其中Pt纳米颗粒（NPs）被完全封装到3DOM的骨架中。 ZIF-8 / SiO ₂由表面连续的ZIF-8外壳组成。此外，发现选择合适的N，N-二甲基甲酰胺（DMF）：H ₂ O和SiO _2的体积比内含物对于诱导3DOM结构上连续ZIF-8壳的原位成核和生长以及防止3DOM结构坍塌至关重要。至关重要的是，由于ZIF-8壳对骨架的分子筛作用，获得的3DOM-Pt @ ZIF-8 / SiO ₂对正己烯和顺式环辛烯的加氢反应具有高尺寸选择性。