TY - JOUR
T1 - Modeling CO and N 2 adsorption at Cr surface species of phillips catalyst by hybrid density functional
T2 - effect of Hartree-Fock exchange percentage
AU - Damin, Alessandro
AU - Vitillo, Jenny G.
AU - Ricchiardi, Gabriele
AU - Bordiga, Silvia
AU - Lamberti, Carlo
AU - Groppo, Elena
AU - Zecchina, Adriano
PY - 2009/12/31
Y1 - 2009/12/31
N2 - In this article, we present a computational study of the structure and vibrational properties of the species formed by the interaction between Cr sites of Phillips catalyst and probe molecules (CO, N 2). The vibrational properties of these surface species, intensively investigated in the past, form a very rich and ideal set of experimental data to test computational approaches. By adopting the X 4Si 2O 3Cr (X = H, OH, F) cluster as a simplified model of the (≡SiO) 2Cr(II) species present at the surface of the real catalyst, we found that the B3LYP hybrid functional (containing 20% of Hartree-Fock exchange), when applied to this model, is unable to reproduce with reasonable accuracy the currently available experimental data (principally coming from IR spectroscopy). Better agreement is obtained when the percentage of Hartree-Fock exchange is increased (up to 35-40%).
AB - In this article, we present a computational study of the structure and vibrational properties of the species formed by the interaction between Cr sites of Phillips catalyst and probe molecules (CO, N 2). The vibrational properties of these surface species, intensively investigated in the past, form a very rich and ideal set of experimental data to test computational approaches. By adopting the X 4Si 2O 3Cr (X = H, OH, F) cluster as a simplified model of the (≡SiO) 2Cr(II) species present at the surface of the real catalyst, we found that the B3LYP hybrid functional (containing 20% of Hartree-Fock exchange), when applied to this model, is unable to reproduce with reasonable accuracy the currently available experimental data (principally coming from IR spectroscopy). Better agreement is obtained when the percentage of Hartree-Fock exchange is increased (up to 35-40%).
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U2 - 10.1021/jp902650m
DO - 10.1021/jp902650m
M3 - Article
C2 - 19610622
AN - SCOPUS:73949094814
SN - 1089-5639
VL - 113
SP - 14261
EP - 14269
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 52
ER -