Interaction of SrO-terminated SrTiO3 surface with oxygen, carbon dioxide, and water
Interaction of SrO-terminated SrTiO3 surface with oxygen, carbon dioxide, and water
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SrO 封端的 SrTiO3 表面与氧气、二氧化碳和水的相互作用
DOI：
10.1039/c8ta05177a
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发表时间：
2018
影响因子：
11.9
通讯作者：
Kilner John
中科院分区：
文献类型：
--
作者：
Staykov Aleksandar;Fukumori Shun;Yoshizawa Kazunari;Sato Kenta;Ishihara Tatsumi;Kilner John
使用第一原理理论方法和表面分析技术研究了 SrO 封端的 SrTiO3 表面与分子二氧化碳和水的相互作用。我们研究了表面 SrCO3 层的形成以及 H2O 与 SrO 表面相互作用的各种可能产物，例如表面化学吸附水和表面氢氧化物层的形成。从理论上和实验上解释了 CO2 和 H2O 的共吸附，表明其产物遵循复杂的温度依赖性，因此，碳酸盐和表面化学吸附水之间的表面组成可能有所不同。我们的理论模拟表明，气相中水分子的存在可能通过氢键机制稳定过渡态的表面氧物种，从而有助于分子氧/晶格氧交换反应。结果，分子氧解离的活化势垒降低，导致表面交换速率常数增加。我们的研究表明，SrO 封端的 SrTiO3 表面不是静态的，而是动态响应外部因素，如气体成分、湿度和温度。因此，通过交换速率的增加或减少，表面相可以显示与分子氧的表面交换反应的不同趋势。
The interaction of SrO terminated SrTiO3 surface with molecular carbon dioxide and water has been investigated using first-principle theoretical methods and surface analysis techniques. We have studied the formation of a surface SrCO3 layer and various possible products of H2O interaction with the SrO surface, such as, surface chemisorbed water and the formation of a surface hydroxide layer. The co-adsorption of CO2 and H2O was explained both theoretically and experimentally showing that its products follow a complex temperature dependence and as a result, the surface composition may vary between carbonate and surface chemisorbed water. Our theoretical simulations have shown that the presence of water molecules in the gas phase might assist the molecular oxygen/lattice oxygen exchange reaction by stabilization of the surface oxo species in the transition state with a hydrogen bond mechanism. As a result, the activation barrier for molecular oxygen dissociation is decreased leading to an increase in the surface exchange rate constant. Our study demonstrates that the SrO terminated SrTiO3 surface is not static but instead, dynamically responds to external factors such as gas composition, humidity, and temperature. As a result, the surface phases can show different trends for the surface exchange reaction with molecular oxygen by either an increase or decrease in the exchange rate.