FTIR study of adsorption, thermal reactions and photochemistry of benzene on powdered TiO2
FTIR study of adsorption, thermal reactions and photochemistry of benzene on powdered TiO2
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DOI：
10.1039/b104926g
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发表时间：
2001
影响因子：
3.3
通讯作者：
W. Wu;Li-Fen Liao;Chen-Fu Lien;Jong‐Liang Lin
中科院分区：
文献类型：
--
作者：
W. Wu;Li-Fen Liao;Chen-Fu Lien;Jong‐Liang Lin
使用傅里叶变换红外光谱研究了苯在粉末状 TiO2 上的吸附、热反应和光化学。苯通过其π电子与表面Ti4+离子相互作用而被吸附，即使当TiO2温度升高至400℃时苯仍保持稳定。然而，在O2存在下，它会热分解为H2O(g)、CO(g)和CO2(g)，并且在低于∽225°C时发生解离。通过苯酚和碘苯的吸附研究发现，苯在TiO2上光氧化时，表面产生苯氧基，并且在H2O或O2存在下，苯氧基的数量大大增加。苯在氧气中的光反应也可产生其他含有羰基或羧酸酯基团的表面产物。目前的原位研究表明，先前研究中苯光氧化后使用溶剂从 TiO2 催化剂中提取的产物可能无法揭示光照射过程中在表面形成的真实产物。
The adsorption, thermal reactions, and photochemistry of benzene on powdered TiO2 have been investigated using Fourier-transform infrared spectroscopy. Benzene is adsorbed with its π electrons interacting with the surface Ti4+ ions, and is stable even when the TiO2 temperature is increased to 400°C. However, it is subject to thermal decomposition to H2O(g), CO(g) and CO2(g) in the presence of O2 and the dissociation occurs below ∽225°C. With the aid of an adsorption study of phenol and iodobenzene, it is found that phenoxy groups are generated on the surface in the photooxidation of benzene on TiO2 and the amount greatly increases in the presence of H2O or O2. Other surface products containing carbonyl or carboxylate groups are produced as well for benzene photoreaction in O2. The present in situ study shows that the products extracted using solvents from TiO2 catalysts after photooxidation of benzene in previous investigations may not reveal the real products formed on the surface during photoillumination processes.