ZnO模型催化体系表面化学的STM研究

项目名称： ZnO模型催化体系表面化学的STM研究

项目编号： No.91545128

项目类型： 重大研究计划

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 邵翔

作者单位： 中国科学技术大学

项目金额： 80万元

中文摘要： ZnO在光电、传感、能源及催化方面应用广泛，是以合成气为原料制备甲醇的重要催化剂，对碳基能源转化问题中所涉及的各种小分子的活化转化有着重要催化作用。然而ZnO表面相关催化反应的基元过程和反应机制仍很不清楚，严重缺乏分子层面的直接研究。本项目旨在利用低温扫描隧道显微镜的超高空间分辨和电子结构探测能力，以原子级平整且稳定的ZnO(10-10)面为研究对象，直接从原子分子水平研究包括甲醇合成及分解、CO2活化转化等过程中所涉及的各种小分子及活性金属的吸附和反应等。项目中将特别关注ZnO单晶表面各种缺陷的结构和物理化学性质。同时将尝试在金属衬底上制备同一取向的ZnO单晶化薄膜，探索通过控制表界面的结构、组成、缺陷、掺杂、膜厚等实现对ZnO薄膜表面化学的调控。通过比较研究单晶与薄膜体系的异同，深入认识ZnO模型体系表面反应的构效关系，最终为设计基于ZnO的新型碳基能源催化体系提供思路。

中文关键词： 扫描隧道显微镜；氧化锌；模型催化体系；表面化学

英文摘要： ZnO is widely used in various fields including the photoelectricity, sensing, energy and catalysis. Particularly ZnO-based catalysts have been used in industrial production of methanol for long time. It has also been reported to catalyze the conversion of many other carbonaceous molecules into higher-grade organics. However, the fundamental surface science researches about ZnO is still far from satisfying. The detailed understanding of the principle molecular processes still lacks which thus appeals for more inputs especially from the direct single-molecular studies. Here in this project we propose to utilize the low-temperature scanning tunneling microscopy and spectroscopy to look at the chemical processes on the most stable ZnO(10-10) surface, by taking the advantages of resolving both the surface structure and electronic properties at atomic level. With the assistance of in-situ adsorption and reaction techniques, direct submolecular information of how the molecules and metals interact with the ZnO surface and within themselves can be discovered. Moreover, the surface defects will be studied in detail by revealing both the structural and electronic properties, as well as their connections to the molecular adsorption and reactions. In addition to the single crystal studies, ultrathin ZnO films with (10-10) orientation will also be prepared on selected metal substrates. By manipulating the growth parameters during the film preparation, the surface property tailoring is anticipated and carefully researched. Finally the structure-property relationship presented on both ZnO single crystal and ultrathin films can be compared and summarized. The gained insights into the ZnO surface chemistry is expected to assist the design and preparation of new type ZnO-based catalyst which may contribute better in dealing with important catalytic issues involved in energy problems.

英文关键词： STM;zinc oxide;model catalyst;surface chemistry