Natural bond orbital analysis of the interaction of H[sub 2] with MgO and LiMgO clusters

Journal Article · Thu Nov 03 04:00:00 EST 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100095a046· OSTI ID:6730208

Anchell, J L; Glendening, E D ^[1]

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1. Pacific Northwest Lab., Richland, WA (United States)

Many interesting phenomena have been observed regarding the mechanism of adsorbate interactions with MgO and Li-doped MgO. This investigation seeks theoretical explanations for several of these phenomena using ab initio methods and the natural bond orbital approach with H[sub 2] as a probe molecule on small MgO and Li/MgO clusters. We find that electrostatic effects largely determine the preference of H[sub 2] chemidissociation at low-coordinated sites and account for the positive cooperativity calculated for multiple dissociation events at neighboring surface sites. We also find that charge transfer and polarization determine the accessibility of a particular dissociation channel on MgO and Li/MgO. The H[sub 2] probe molecule acts simultaneously as an electron acceptor and donor along those pathways having low activation barriers. Li-doping enhances the catalytic activity of MgO by creating O[sup [minus]] centers that strengthen donor-acceptor interactions with H[sub 2]. 29 refs., 9 figs., 1 tab.

• DOE Contract Number: FG06-89ER75522; FG06-92RL12451
• OSTI ID: 6730208
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:44; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
661300 -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ADSORPTION
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
CALCULATION METHODS
CATALYSTS
CHALCOGENIDES
CHARGE TRANSPORT
CHEMICAL REACTION KINETICS
CRYSTAL DOPING
DISSOCIATION
ELEMENTS
HYDROGEN
ION PAIRS
KINETICS
LITHIUM COMPOUNDS
MAGNESIUM COMPOUNDS
MAGNESIUM OXIDES
MOLECULAR ORBITAL METHOD
NONMETALS
OXIDES
OXYGEN COMPOUNDS
POLARIZATION
REACTION KINETICS
SORPTION
SURFACE PROPERTIES