Periodic Density Functional LDA and GGA Study of CO Adsorption at the (001) Surface of MgO

Abstract

The deficiencies of the local density approximation (LDA) to describe weakly adsorbed species on ionic surfaces are exposed in the current study of CO on the (001) surface of MgO. We applied a periodic formulation of density functional theory with crystal orbitals and charge density expanded as linear combinations of atomic orbitals of Gaussian form. The binding was investigated for four orientations of the CO molecule: either the carbon or oxygen atom of CO down over either the surface magnesium cation or oxygen anion. We find that the carbon down over the magnesium cation is the only noticeably attractive configuration, when basis set superposition error is corrected for, and we estimate the binding energy of CO to be 1.9 kcal/mol for the Perdew, Burke, and Enzerhof (PBE96) functional. The binding energy obtained in the LDA approximation is as large as 7.4 kcal/mol. For the C-down-over-Mg configuration, the CO stretching frequency shift is only 4 cm-1 for the PBE96 functional. This binding energy, vibrational shift, and our analysis of density of states indicate that little chemical bonding accompanies the adsorption. The values of our binding energy and vibrational shift support a suggestion by Nygren and Pettersson [J. Chem. Phys. 1996, 105, 9339] that the CO adsorption discussed by He et al. [Surf. Sci. 1992, 261, 164] actually takes place at defect sites on the (001) surface of MgO.

CO adsorption on metal‐oxide surfaces doped with transition‐metal adatoms

“…Similarly, for the change in the CO vibrational frequency due to the adsorption, similar calculations have been performed in Refs. [25,27,40,41]. Our results match the other results, when available, quite well.…”

“…[40] reports an adsorption energy of 0.02 eV, Ref. [41] 0.08 eV, and Ref. [42] reports values between 0.0 and 0.48 eV depending on the calculation method, with 0.07 eV considered the most accurate result by the authors of Ref.…”

Roles of oxygen vacancy in the adsorption properties of CO and NO on Cu2O(111) surface: Results of a first-principles study

“…Both CO and NO are used as common probe molecules in surface science to obtain fundamental information about the gas-surface interactions, adsorption sites, and reactive dynamics on a variety of metals [1][2][3][4][5][6], semiconductors [7][8][9][10][11], and insulator surfaces. Moreever, CO and NO are both one of the most hazardous products released by car exhausts.…”

Structure and property correlation for Ag deposition on α-Al2O3—a first principle study

“…DFT (density functional theory) methods have begun its venture in oxides somewhat later but progressed in a rapid manner; hence, a number of studies have been reported in the last decade on oxides as well as other materials [18][19][20][21][22][23][24][25]. In the last couple of years, there have been considerable progresses in the area [26][27][28][29][30][31][32] of electronic and structural properties of mixed metal oxides using first principle density functional theory.…”