Differential heat of chemisorption. 1. Chemisorption of water on zinc oxide and titanium dioxide
Differential heat of chemisorption. 1. Chemisorption of water on zinc oxide and titanium dioxide
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DOI：
10.1021/j100498a015
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发表时间：
1978-05
期刊：
影响因子：
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通讯作者：
M. Nagao;K. Yunoki;H. Muraishi;T. Morimoto
中科院分区：
文献类型：
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作者：
M. Nagao;K. Yunoki;H. Muraishi;T. Morimoto
在28 ℃下测量具有不同量表面羟基的ZnO和TiO 2（金红石）样品的水中浸没热，由此计算水化学吸附的积分热。通过对化学吸附积分热与预化学吸附水量的曲线进行微分，得到水化学吸附的微分热，即羟基形成的热。TiO 2表面的差热随化学吸附水的增加而减小，表明TiO 2表面具有普通的非均匀性。然而，ZnO给出了一个不寻常的微分热曲线，表现出在单层覆盖附近的最大值。这种现象是最好的understoodin的额外贡献的表面羟基之间形成的发达的（10 0）平面上的ZnO，在模型的基础上假设的吸附异常系统ZnO-H2O的说明。
The heat of immersion in water was measured at 28 C on samples of ZnO and Ti02 (rutile) having different amounts of surface hydroxyls, from which the integral heat of water chemisorption was calculated. Thedifferential heat of water chemisorption, ie, that of formation of hydroxyl groups, was obtained by differentiating the curve of the integral heat of chemisorption vs. the amount of prechemisorbed water. The differential heat on Ti02 decreases with increasing amountof chemisorbed water, suggesting an ordinary type of surface heterogeneity. However, ZnO gives an unusual differential heat curve which exhibits a maximum in the vicinity of monolayer coverage. This phenomenon is best understoodin terms of the additional contribution of mutual hydrogen bondings between surface hydroxyls formed on the well-developed (10 0) plane of ZnO, on the basis of the model postulated previously for the elucidation of an adsorption anomaly in the system ZnO-H20.