Morra Elena, Signorile Matteo, Salvadori Enrico, Bordiga Silvia, Giamello Elio, Chiesa Mario
Department of Chemistry, University of Torino, Via Giuria, 7, 10125, Torino, Italy.
Angew Chem Int Ed Engl. 2019 Sep 2;58(36):12398-12403. doi: 10.1002/anie.201906488. Epub 2019 Aug 19.
Determining structural models is pivotal to the rational understanding and development of heterogeneous catalytic systems. A paradigmatic case is represented by open-shell metals supported on oxides, where the catalytic properties crucially depend on the nature of the metal-oxygen bonds and the extent of charge and spin transfer. Through a combination of selective O isotopic enrichment and the unique properties of open-shell s-state monovalent Group 12 cations, we derive a site-specific topological description of active sites in an MFI zeolite. We show that just a few selected sites out of all possible are populated and that the relative occupancies depend on the specific properties of the metal, and we provide maps of charge and spin transfer at the metal-oxygen interface. This approach is not restricted to zeotype materials, rather it is applicable to any catalysts supported on oxygen-containing materials.
确定结构模型对于合理理解和开发多相催化体系至关重要。一个典型的例子是负载在氧化物上的开壳层金属，其催化性能关键取决于金属 - 氧键的性质以及电荷和自旋转移的程度。通过选择性O同位素富集与开壳层s态单价第12族阳离子的独特性质相结合，我们得到了MFI沸石中活性位点的位点特异性拓扑描述。我们表明，在所有可能的位点中只有少数被占据，并且相对占有率取决于金属的特定性质，同时我们提供了金属 - 氧界面处的电荷和自旋转移图。这种方法不仅限于沸石型材料，而是适用于任何负载在含氧化合物上的催化剂。
