The present paper describes the dynamics of hexane cracking in ZSM-5 and methanol oxidation on va... more The present paper describes the dynamics of hexane cracking in ZSM-5 and methanol oxidation on vanadium beta zeolite (V-BEA) by means of ab-initio Molecular Dynamics (AIMD) and transition path sampling (TPS).
... Frauenheim, G. Grathwohl, J. Caro und M. Wark. New proton conducting hybrid membranes for HT-... more ... Frauenheim, G. Grathwohl, J. Caro und M. Wark. New proton conducting hybrid membranes for HT-PEMFC systems based on polysiloxanes and ... P. Koskinen, H. Hakkinen, G. Seifert, S. Sanna, T. Frauenheim und M. Moseler. Density-functional based tight-binding study of small ...
The geometry, energetic, and spectroscopic properties of molecular structures of silica-supported... more The geometry, energetic, and spectroscopic properties of molecular structures of silica-supported niobium oxide catalysts are studied using periodic density functional calculations (DFT) and compared with experimental data. The calculations are done for Nb oxide species inserted or grafted in/on an amorphous hydroxylated silica surface. Different positions of the Nb atom/atoms in the silica structure have been investigated. By means of DFT calculations the geometry and the degree of hydration of Nb oxide species with oxidation state +5 have been studied. The local Nb geometry depends on different parameters such as the number of Nb-O-Si groups vs. Nb-O-H groups, the formation of H bonds and the distance between Nb atoms. The interaction between the oxide and silanol groups occurs by formation of Si-O-Nb bonds with chemically and thermally stable Brønsted and Lewis acid sites. UV-Vis, reflection absorption infrared vibrational spectra (RAIRS) as well as various thermodynamic properties have also been investigated in order to get a better insight into the system studied and to provide support to possible experimental studies.
The present paper describes the dynamics of hexane cracking in ZSM-5 and methanol oxidation on va... more The present paper describes the dynamics of hexane cracking in ZSM-5 and methanol oxidation on vanadium beta zeolite (V-BEA) by means of ab-initio Molecular Dynamics (AIMD) and transition path sampling (TPS).
... Frauenheim, G. Grathwohl, J. Caro und M. Wark. New proton conducting hybrid membranes for HT-... more ... Frauenheim, G. Grathwohl, J. Caro und M. Wark. New proton conducting hybrid membranes for HT-PEMFC systems based on polysiloxanes and ... P. Koskinen, H. Hakkinen, G. Seifert, S. Sanna, T. Frauenheim und M. Moseler. Density-functional based tight-binding study of small ...
The geometry, energetic, and spectroscopic properties of molecular structures of silica-supported... more The geometry, energetic, and spectroscopic properties of molecular structures of silica-supported niobium oxide catalysts are studied using periodic density functional calculations (DFT) and compared with experimental data. The calculations are done for Nb oxide species inserted or grafted in/on an amorphous hydroxylated silica surface. Different positions of the Nb atom/atoms in the silica structure have been investigated. By means of DFT calculations the geometry and the degree of hydration of Nb oxide species with oxidation state +5 have been studied. The local Nb geometry depends on different parameters such as the number of Nb-O-Si groups vs. Nb-O-H groups, the formation of H bonds and the distance between Nb atoms. The interaction between the oxide and silanol groups occurs by formation of Si-O-Nb bonds with chemically and thermally stable Brønsted and Lewis acid sites. UV-Vis, reflection absorption infrared vibrational spectra (RAIRS) as well as various thermodynamic properties have also been investigated in order to get a better insight into the system studied and to provide support to possible experimental studies.
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