Kinetic energy of structural protons in silica xerogels

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• 作者：R. Moreh^a ; ^{moreh@bgu.ac.il} ; D. Nemirovsky^b ; J. Zabicky^c
• 关键词：Proton kinetic energies ; Silica xerogel ; Ab initio calculations ; Infrared spectroscopy
• 刊名：Surface Science
• 出版年：2012
• 期刊代码：104_00396028
• 类别：ch
• 出版时间：July, 2012
• 卷：606
• 期：13-14
• 页码：1088-1092
• 文件大小：213 K

摘要

The kinetic energies of the protons in the silanol groups (Si-OH units) of silica xerogels were deduced by ab initio calculations using the basis set mp2/6-311G**. The silanol groups were simulated using the Si(OH)₄ unit. The calculated result of the H-kinetic energy was found to be 150 meV, which is ~ 50%smaller than a recently reported experimental value for porous silica xerogels. For comparison, the same calculations of the proton kinetic energies of other H-containing molecules such as H₂O and CH₄ (being also ~ 150 meV) were found to be in excellent agreement with measurements. Possible reasons for the huge deviations in the case of the silanols are discussed.