TITLE

Comparing ab initio computed energetics with thermal experiments in surface science: CO/MgO(001)

AUTHOR(S)
Nygren, Martin A.; Pettersson, Lars G. M.
PUB. DATE
November 1996
SOURCE
Journal of Chemical Physics;11/22/1996, Vol. 105 Issue 20, p9339
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Early measurements of the binding energy of CO/MgO(001) gave low values, 0.15–0.17 eV, for the regular site, while later experiments using two independent experimental techniques (temperature programmed desorption and Clausius–Clapeyron plots) have given a much higher value, 0.43–0.45 eV. Theory has shown the opposite trend: early calculations gave a value of 0.38 eV, while the latest results are 0.07–0.11 eV. We have performed a careful theoretical analysis of the Clausius–Clapeyron experiment which is found to be in the assumed equilibrium region. Quantum chemical cluster modelling of regular, step, and corner sites show that only a low-coordinated (corner) site can fit both the measured binding energy and vibrational frequency shift. Accurate embedding techniques with full account of the crystal potential and a high-level treatment of dynamical correlation using large basis sets have been used. Effects of relaxation of the step have been investigated using atomistic simulation techniques. The binding energies (corrected for basis set superposition errors) are computed as 0.08, 0.18, and 0.48 eV for regular, step and corner sites, respectively. Theoretical temperature programmed desorption spectra have been generated and show that desorption from regular and step sites should be expected at 40 and 80 K, respectively. At a corner site the molecule is tilted at 45° to the normal. From angle-resolved near-edge extended x-ray absorption fine structure spectroscopy of CO/NiO(100) the molecule has been found to be vertical. Theoretical spectra have been generated including averaging over the frustrated rotations; agreement with the experimental intensity distribution is obtained also for the tilted (at 0 K) geometry. It is suggested that the oxide films contain a high density of defects. © 1996 American Institute of Physics.
ACCESSION #
7639814

 

Related Articles

  • Structures and stability of CO layers on the MgO(001) surface. Sallabi, A. K.; Sallabi, A.K.; Jack, D. B.; Jack, D.B. // Journal of Chemical Physics;3/15/2000, Vol. 112 Issue 11 

    Monte Carlo simulations of CO/MgO(001) show that below 41 K the CO molecules form a c(4x2) structure with six molecules per unit cell distributed into two kinds of adsorption sites: a perpendicular site and a tilted site (polar angle of 31°). Both sites are localized near Mg[sup 2+] ions. The...

  • Bonding between CO and the MgO(001) surface: A modified picture. Nygren, Martin A.; Pettersson, Lars G. M.; Barandiarán, Zoila; Seijo, Luis // Journal of Chemical Physics;2/1/1994, Vol. 100 Issue 3, p2010 

    The interaction energy and equilibrium distance for adsorption of CO on a perfect MgO(001) surface has been calculated, using a cluster approach for representing the surface. The cluster size has been varied from one single Mg2+ ion up to Mg14O5. Ab initio model potentials (AIMP) were used to...

  • Accurate surface and adsorption energies from many-body perturbation theory. Schimka, L.; Harl, J.; Stroppa, A.; Grüneis, A.; Marsman, M.; Mittendorfer, F.; Kresse, G. // Nature Materials;Sep2010, Vol. 9 Issue 9, p741 

    Kohn–Sham density functional theory is the workhorse computational method in materials and surface science. Unfortunately, most semilocal density functionals predict surfaces to be more stable than they are experimentally. Naively, we would expect that consequently adsorption energies on...

  • Good performance of the M06 family of hybrid meta generalized gradient approximation density functionals on a difficult case: CO adsorption on MgO(001). Valero, Rosendo; Gomes, José R. B.; Truhlar, Donald G.; Illas, Francesc // Journal of Chemical Physics;9/28/2008, Vol. 129 Issue 12, p124710 

    The adsorption of CO on Mg(001) constitutes a challenge for current density functional approximations because of its weak interaction character. In the present work we show that the M06-2X and M06-HF exchange-correlation functionals are the first ones to provide a simultaneously satisfactory...

  • Using electrochemical process to mineralize CO and separate Ca/Mg ions from hard water to produce high value-added carbonates. Xie, Heping; Liu, Tao; Hou, Zhengmeng; Wang, Yufei; Wang, Jinlong; Tang, Liang; Jiang, Wen; He, Yang // Environmental Earth Sciences;Jun2015, Vol. 73 Issue 11, p6881 

    CO mineralization is a promising utilization option for reducing CO emissions. Hard water (e.g. seawater, salt water and brine) rich in Ca and Mg ions, has potential for fixation of CO. But to date there is no effective way to use these ions for CO mineralization. In this paper, a novel method...

  • Therapeutic effect of magnesium sulphate on carbon monoxide toxicity-mediated brain lipid peroxidation. YAVUZ, Y.; MOLLAOGLU, H.; YÜRÜMEZ, Y.; ÜCOK, K.; DURAN, L.; TÜNAY, K.; AKGÜN, L. // European Review for Medical & Pharmacological Sciences;Sup, Vol. 17 Issue S1, p28 

    BACKGROUND: Carbon monoxide (CO) toxicity primarily results from cellular hypoxia caused by impedance of oxygen delivery. Studies show that CO may cause brain lipid peroxidation and leukocyte-mediated inflammatory changes in the brain. AIM: The aim of this study was to investigate whether...

  • Electronic excitations of CO adsorbed on MgO(001). Wang, N.-P.; Rohlfing, M.; Krüger, P.; Pollmann, J. // Applied Physics A: Materials Science & Processing;2004, Vol. 78 Issue 2, p213 

    We report ab initio calculations of the quasiparticle band structure and the optical excitation spectrum of bulk MgO, the MgO(001) surface, and CO molecules adsorbed on MgO(001). Many-body exchange and correlation effects are included within the GW approximation of the electron self-energy...

  • Ni-based catalyst derived from Ni/Mg/Al hydrotalcite-like compounds and its activity in the methanation of carbon monoxide. Li, Zhenhua; Bian, Li; Zhu, Qiujun; Wang, Weihan // Kinetics & Catalysis;Mar2014, Vol. 55 Issue 2, p217 

    The supported Ni-based catalyst is widely used in the methanation process. Nevertheless, the major disadvantages of this catalyst are a poor behavior in the water-gas-shift ( WGS) reaction and the deactivation at higher temperatures. A new kind of catalyst, nickel-containing oxides catalyst...

  • Electron correlation contribution to the physisorption of CO on MgF2(110). Hammerschmidt, Lukas; Müller, Carsten; Paulus, Beate // Journal of Chemical Physics;3/28/2012, Vol. 136 Issue 12, p124117 

    We have performed CCSD(T), MP2, and DF-LMP2 calculations of the interaction energy of CO on the MgF2(110) surface by applying the method of increments and an embedded cluster model. In addition, we performed periodic HF, B3LYP, and DF-LMP2 calculations and compare them to the cluster results....

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics