氧化铈表面氧空位及与水反应机制的高分辨研究

氧化铈因其优越的氧化还原能力广泛应用在包括电解水、水气变换以及三效催化等诸多工业催化剂中，氧空位是氧化铈基催化剂的重要活性位点或活性来源，其中水与表面氧空位的相互作用是多个催化过程的关键中间步骤，对产物的选择性也至关重要。然而氧化铈的氧空位与阳离子的原子尺度结构存疑，其与水的作用机制至今也没有得到清晰的图像，尤其是液固界面的反应机理缺乏研究。本项目拟建立以小分子探针通过近常压光电子能谱、扫描隧道显微镜以及qPlus原子力显微镜等技术从原子水平识别与解析氧化铈单晶氧空位与阳离子结构、迁移及性质的研究方法，并深入研究气固、液固界面下水在Ceria(111)上的反应机制及构效关系，帮助理解氧化铈基催化剂上电解水、水气变换等复杂反应过程的基元步骤和机理，为往后设计和发展高效氧化铈基催化剂提供新思路。

Cerium oxide is widely used in the industrial applications such as hydrogen generation by electrolysis of water, water-gas-shift reaction, and the automotive three-way catalyst because of its high reactivity. The oxygen vacancies are the important active sites or sources in the ceria-based catalysts. As in many of these catalytic reactions, water plays an important role either as the reactants or the key intermediates, which could be crucial for the selectivity of the products. However, the atomic structure of oxygen vacancies and Ce ions, as well as the reaction mechanism for water, especially in aqueous phase, on the ceria surface remains unclear. On the one hand, this project intends to establish the research method to recognize and reveal the structure, migration, and the characteristics of the oxygen vacancies and Ce ions in surface at atomic scale with the help of small probing molecules via AP-XPS, STM and qPlus AFM. On the other hand, it wants to investigate the reaction mechanism between the surface oxygen vacancies and water both at gas-solid and liquid-solid interface. We aim to obtain the structure-activity relationship between the oxygen vacancies and water with different physical interface, and help to understand the fundamental steps in the reactions such as water electrolysis and water-gas-shift reaction. Thereby, this work can provide fresh ideas for the design and development of highly efficient ceria-based catalysts.