Electron Spin Resonance Studies of the Surface Chemistry of Rutile
Electron Spin Resonance Studies of the Surface Chemistry of Rutile
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DOI：
10.1021/ja00974a001
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发表时间：
1966-11
影响因子：
15
通讯作者：
R. Iyengar;M. Codell;J. Karra;J. Turkevich
中科院分区：
文献类型：
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作者：
R. Iyengar;M. Codell;J. Karra;J. Turkevich
本文研究了在空气中干燥的沉淀金红石粉末的电子自旋共振谱。在空气中干燥的样品获得的两个信号（均为三重峰）归因于表面上O2+的存在。在较高温度下的放气导致两个三重态的消失和一个新的不对称信号的出现，由于Ti（III）离子的形成。实验还表明，这些Ti（III）离子不占据间隙位置，而是存在于规则的晶格位置。如果在500 ℃下对样品进行3小时的除气，则产生的Ti（III）离子靠近表面，并且在室温下在氧气进入时完全氧化为Ti（IV）。然而，使用氢气还原Ti 〇 2导致甚至在材料的本体中形成Ti（III）离子。最后，在初始高温脱气之后在室温下暴露于氧气的样品的脱气产生新的信号（双峰），其被识别为表面处的O2物质。
The electron spin resonance spectra of precipitated rutile powders dried in air and subjected to various gas and vacuum treatments have been studied. Two signals (both triplets) obtainedwith the sample dried in air have been attributed to the presence of 02+ on the surface. Outgassing at higher temperatures leads to the disappearance of the two triplets andappearance of a new asymmetric signal, due to formation of Ti (III) ions. Experi-ments also indicatethat these Ti (III) ions do not assume interstitial positions but are present at regularlattice positions. If outgassing of the sample is done at 500 for 3 hr the Ti (III) ions produced are close to the surface and are completely oxidized to Ti (IV) at room temperature on admission of oxygen. However, use of hydrogen gas for reducing Ti02 leads to formation of Ti (III) ions even in the bulk of the material. Finally, outgassing of a sample exposed to oxygen at room temperature following an initial high-temperature outgassing yields a new signal (doublet) which is identified as the 02~ species at the surface.