Theoretical study of MgO(001) surfaces: Pure, doped with Fe, Ca, and Al, and with and without adsorbed water

Abstract

Ab initio calculations of large cluster models have been performed in order to study water adsorption at the five-fold coordinated adsorption site on pure Mg(001) and MgO(001) surfaces doped with Fe, Ca, and Al. The geometric parameters of the adsorbed water molecule have been optimized preparatory to analysis of binding energies, charge transfer, preferential sites of interaction, and bonding distances. We have used Mulliken population analysis methods in order to analyze charge distributions and the direction of charge transfer. We have also investigated energy gaps, HOMO energies, and SCF orbital energies as well as the acid-base properties of our cluster model. Numerical results are compared, where possible, with experiment and interpreted in the framework of various analytical models.

Effect of embedding MgO and Al2O3 nanoparticles in the precursor on the pore characteristics of PAN based activated carbon nanofibers

“…Likewise, a similar reasoning could be put forward for the normal grade of MgO and Al 2 O 3 nanoparticles. This highlights the importance of the specific surface area of the metal oxide nanoparticles which determines the degree of accessibility to the lowcoordinated metal atoms functioning as catalyst during pyrolysis [22,23]. 4.…”

Small Group IIa–VIa Clusters and Related Systems: A Theoretical Study of Physical Properties, Reactivity, and Electronic Spectra

“…[50,52] The transition between clusters and bulk was investigated. [76] The band structure [7] of BeO and MgO surfaces [26,44a,44b] (and their infrared spectra [37] ), as well as doped MgO, [26] were also subjects of scrutiny. Trends in the series BeO through BaO [10] and BeS through BeTe [15,19,23] were described.…”

Structural and Electronic Properties of Frenkel and Schottky Defects at the MgO{100} Surface: Spin Polarization, Mid-Band Gap States, and Charge Trapping at Vacancy Sites

“…There have been numerous computational studies on MgO surface defects. Apart from Frenkel and Schottky defects, − which are the topic of our study and of which we will discuss the available literature into more detail below, calculations have been performed on terrace steps or edges, O and Mg monovacancies, − adatoms, dopants, , and on the adsorption of molecular species onto particular surface defects. ,, The presence of defects is strongly related to the overall electronic structure of an MgO material, as has been shown by Richter et al, who investigated the influence of doping on the formation energy and concentration of O surface vacancies through a combination of computational methodologies, and by Uchino and Yoko, who investigated point defects in nanoscale blocks of MgO and found a collection of spin-polarized states depending on the presence and distribution of Mg vacancies . A recent example of a molecule adsorption study on MgO surface defects is the work by Alvim et al, who investigated proton migration on perfect, vacancy-defected, and Al-doped MgO(001) surfaces…”