Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Electronic factors determining the methane bond breaking process on small aluminum clusters
Δημιουργός/Συγγραφέας:	Alexandrou E.I. Groß A. [EL] Μπακάλης, Ναούμ Χ.[EN] Bacalis, Naoum C.
Εκδότης:	John Wiley and Sons Inc.
Ημερομηνία:	2019
Γλώσσα:	Αγγλικά
ISSN:	0020-7608
DOI:	10.1002/qua.26003
Περίληψη:	In order to understand the catalytic activity of small metal clusters as a function of their size, we have studied the interaction of CH4 with Al4 and Al5 neutral and charged clusters, as well as neutral thermally expanded clusters in the two lowest lying spin states, using density functional theory. These calculations, via extended search, are used to determine the stable positions of H and CH3 near the cluster, and the transition state to break the H─CH3 bond. In order to understand the factors underlying the reactivity of the clusters, we have analyzed the electronic structure at the transition state. By an analysis of the change of the electronic density of states close to the transition state, we identify the orbitals involved in the bond breaking process. In conjunction with our previous studies of Al2 and Al3 clusters, we find that the small Al clusters, except for Al5, lower the CH3─H dissociation barrier with respect to the gas-phase value, although Al lacks occupied d-orbitals. Still, Al5 does not catalyze methane bond breaking, which is attributed to the required interaction with low-lying Al sp-states. Furthermore, in all cases where stable methyl-aluminum-hydrides are possible, the recombinative desorption of methane is studied by vibrational analysis and application of transition state theory.
Τίτλος πηγής δημοσίευσης:	International Journal of Quantum Chemistry
Τόμος/Κεφάλαιο:	119
Τεύχος:	21
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Ατομική φυσική (συμπ. μοριακή φυσική, σχετικότητα, κβαντική θεωρία και φυσική στερεάς κατάστασης)[EN] Atomic physics (Incl. molecular physics, relativity, quantum theory, and solid state physics)
Λέξεις-Κλειδιά:	aluminum clusters catalysis computer simulations density functional calculations methane
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2019 Wiley Periodicals, Inc.
Σημειώσεις:	2005-01330081, 64769; European Commission, EC: 2000-2006 Work supported by Action 8.3.1 Reinforcement Programme of Human Research Manpower??PENED-2003? (Public expenditure by 90%), co-funded from the European Union by 75% and from the Hellenic State by 25% through the Operational Programme Competitiveness, 2000-2006. Partially supported (by 10%) by Hellenic Petroleum S.A. Partial support of this work through the ?Excellence in the Research Institutes? program, supervised by the General Secretariat for Research and Technology/Ministry of Development, Greece (Phase I and II, Projects 64769 and 2005-01330081), and through project ?Advanced Materials and Devices? (MIS:5002409).
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο