TY - JOUR
T1 - Hydrogen bonding versus coordination of adsorbate molecules on Ti-silicalites
T2 - A density functional theory study
AU - Zhanpeisov, Nurbosyn U.
AU - Anpo, Masakazu
PY - 2004/8/4
Y1 - 2004/8/4
N2 - The present study discusses the results of theoretical calculations obtained at the B3LYP/6-31G* level on the structural, electronic, and energetic properties of Ti-silicalites. Particularly, the relevance of 5T cluster models, either H- or OH-terminated, in large-scale calculations has been critically considered. It was shown that an open surface structure with one OH group and a closed-bulk structure with no bonded OH group at the Ti site are responsible for the observed UV-vis properties of Ti-silicalite materials. Both water and methanol can preferably interact with Ti-silicalites through the H-bonding mechanism, while ammonia can form either H-bonded or coordination complexes. The calculations support the existence of highly dispersed Ti sites in a tetrahedral environment only in Ti-silicalites because an increase in the coordination number of the Ti site by next-neighbor lattice oxygens is the energetically less favorable process.
AB - The present study discusses the results of theoretical calculations obtained at the B3LYP/6-31G* level on the structural, electronic, and energetic properties of Ti-silicalites. Particularly, the relevance of 5T cluster models, either H- or OH-terminated, in large-scale calculations has been critically considered. It was shown that an open surface structure with one OH group and a closed-bulk structure with no bonded OH group at the Ti site are responsible for the observed UV-vis properties of Ti-silicalite materials. Both water and methanol can preferably interact with Ti-silicalites through the H-bonding mechanism, while ammonia can form either H-bonded or coordination complexes. The calculations support the existence of highly dispersed Ti sites in a tetrahedral environment only in Ti-silicalites because an increase in the coordination number of the Ti site by next-neighbor lattice oxygens is the energetically less favorable process.
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U2 - 10.1021/ja0385484
DO - 10.1021/ja0385484
M3 - Article
C2 - 15281837
AN - SCOPUS:3342875500
VL - 126
SP - 9439
EP - 9444
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 30
ER -