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A variety of useful chemical products has been produced by heterogeneous catalysts and the development of novelsurfaces for selective heterogeneous catalysis is one of the most challenging issues in chemistry. The relationshipbetween active metal structures and their catalytic performances is critical to create new efficient catalytic systems,however, heterogeneous surfaces existing several active metal species, reactants, many reaction intermediates, andproducts are so complicated to understand the nature of heterogeneous catalysis in a simple way.
We have developed novel techniques to create regulated metal structures on oxide surfaces for selective catalysisand the relationship between active metal structures on surfaces and their catalytic performances has beeninvestigated by in-situ characterization using synchrotron XAFS.1 The attachment and subsequent stepwise structuraltransformations of metal complexes to oxide surfaces often produce unique metal coordination structures, which aredifferent from those in solutions or crystals, and regulated metal conformations on heterogeneous surfaces can beobtained in a molecular level. In-situ characterization of such molecularly organized metal structures by synchrotronXAFS, XPS, FT-IR, Raman spectroscopy, solid-state NMR etc. provide insights into the roles of active metal centersand reaction mechanism.
In this talk, I will present the design and in-situ characterization of supported metal-complex catalysts on oxidesurfaces: oxide-supported Ir dimer catalysts for transfer hydrogenation2 and molecularly imprinted Ru-complexcatalysts for regioselective epoxidation.3
References
1. M. Tada, S. Muratsugu, M. Kinoshita, T. Sasaki, Y. Iwasawa, J. Am. Chem. Soc., 132, 713 (2010).
2. S. Muratsugu, Y. Kushida, H. Nakai, K. Isobe, T. Sasaki, M. Tada, J. Am. Chem. Soc., submitted.
3. Manuscript in preparation.
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