报告人：Prof. Georgi N. Vayssilov
Since the last decade of the last century quantum chemical methods have become an integral part of the modern chemical research. This presentation includes several examples from my group how the computational modeling complemented successfully experimental studies in clarification of various problems related to zeolites - local structure and stability, spectral characteristics and chemical transformations of guest species.
Traditional research topics of the group are simulations of the structure, spectra and reactivity of transition metal clusters and complexes in zeolites. Earlier we have shown that rhodium, iridium and several other transition metal clusters do not exists as bare clusters in protonic forms of zeolites but they are partially hydrogenated due to reverse hydrogen spillover from the bridging hydroxyl groups. Recently, we explored the stability of the different intermediate species formed after during ethene hydrogenation on small rhodium clusters and identified preferred reaction path for the process. On the other hand our simulations of Rh(I) complexes, combined with experimental studies, has explained the reasons for different catalytic behavior of the carbonyl and nitrosyl complexes.
Recently, a partner group in Caen, France, synthesized nanosized tungsten-containing W-ZSM-5 zeolite which was free of silanol groups. Our contribution was related to clarification how the tungsten species are connected in the structure of the zeolite by computational modeling. The most relevant species was W=O moiety located in tetrahedral framework position.
The talk will include also some other research activities of the group related to modeling of catalytic systems - platinum on ceria, nickel or palladium nanoparticles, etc..
Georgi Vayssilov is Professor in the Faculty of Chemistry and Pharmacy, University of Sofia, Bulgaria. He graduated and received PhD in Chemistry in the same university. In 1998-2000 he was Humboldt research fellow in the Technical University of Munich with Prof. Rösch. The research interests of G. Vayssilov include quantum chemical modelling of catalytic systems, new materials, and related complex systems as transition metal complexes and clusters supported in zeolites, metal-organic frameworks, or on metal oxides. He is author of about 100 scientific publications. He was President of the Federation of European Zeolite Associations and of the Humboldt Union in Bulgaria. Since 2015 Prof. Vayssilov is President of the Executive board of Bulgarian National Science Fund.