Control of strong metal-support interactions in catalysts made of colloidally prepared metal nanoparticles and transition metal oxides

金属纳米晶体的胶体制备通过在合成中使用有机配体，可以高度控制颗粒大小和形状等结构特性。结构控制开启了实现具有高度定义的多相催化性能的负载催化剂的可能性。在资助项目“基于胶体制备的金属纳米颗粒的负载催化剂：通过结构控制的反应控制”的框架下（德文标题：Trägerkatalysatoren）。Reaktionskontrolle（如Strukturkontrolle），胶体制备的pt基纳米晶体在选定的测试反应中在非均相气相催化中的应用潜力进行了研究，重点是有机化合物的加氢。实验成功地证明了双金属纳米粒子的制备以及有机配体的使用确实是对负载型金属纳米粒子的活性和选择性产生积极影响的合适策略。根据这些结果，拟议的延长项目的意图是使用胶体化学方法开发适合研究强金属-支撑相互作用（SMSI效应）的模型系统。目的是创建模型系统，一方面是在真空条件下高度定义的模型催化剂，另一方面是真实的催化剂。在材料方面，应实现单金属和双金属pt基模型催化剂。因此，金属和氧化组分之间接触的性质将系统地改变。这些材料将被详细表征，并作为CO氧化和CO在氢（CO PROX）存在下优先氧化的催化剂进行研究。考虑到这些测试反应，有可能涵盖更广泛的氧化性或还原性反应条件，这可能会对SMSI效应的发生产生重大影响。

The colloidal preparation of metal nanocrystals enables a high degree of control over structural properties such as the particle size and shape by using organic ligands in the synthesis. The structure control opens the possibility to realize supported catalysts with highly defined properties for heterogeneous catalysis. In the framework of the funded project entitled 'Supported Catalysts Based on Colloidally Prepared Metal Nanoparticles: Reaction Control by Structure Control' (German title: 'Trägerkatalysatoren auf Basis kolloidal hergestellter Metallnanopartikel: Reaktionskontrolle durch Strukturkontrolle'), colloidally prepared Pt-based nanocrystals were examined with respect to their application potential in heterogeneous gas phase catalysis in selected test reactions, with the focus on the hydrogenation of organic compounds. It was successfully demonstrated that the preparation of defined bimetallic nanoparticles as well as the usage of organic ligands are indeed suitable strategies to influence in a positive manner on the activity and selectivity of supported metal nanoparticles. Emerging from those results, the intention of the proposed prolongation project is to use the colloidal chemistry approach now to develop model systems suitable to investigate strong metal-support interactions (SMSI effects). The aim is to create model systems situated between highly defined model catalysts under vacuum conditions on the one hand, and real catalysts on the other hand. Concerning the materials, mono- and bimetallic Pt-based model catalysts shall be realized. Thereby, the nature of the contact between the metallic and oxidic components will be systematically varied. The materials will be characterized in detail and investigated as catalysts for CO oxidation and the preferential oxidation of CO in the presence of hydrogen (CO PROX). Considering these test reactions, it is possible to cover a broad range of more oxidative or reductive reaction conditions, which may significantly influence on the occurrence of SMSI effects.