催化科学面临如何清晰地获得多相催化剂的活性中心本质的巨大挑战，阻碍了人们从分子水平设计、构筑新型催化剂以获得所希望的性质。本项目旨在建立对催化剂在工作状态（operando）下获取其活性位点结构信息的差分XAFS实验技术，实现对活性位点原子占所有吸收原子5%以上的高灵敏探测。以CO催化氧化作为模型催化反应，利用差分XAFS研究金属纳米团簇和氧化物催化剂在真实反应条件下的动力学行为，获得在反应物吸附、表面催化反应、反应物脱附等不同阶段催化剂活性位点的原子和电子结构特征。再利用色谱和红外原位技术探测催化反应过程中反应物气体分子的变化，并结合理论计算分析，从原子分子水平上深入探讨催化剂活性中心的结构特点，指认活性位点原子与反应物所形成的中间体及其催化反应机理，明确它们与催化活性、选择性之间的联系，并与实验相印证，为从源头设计和构筑下一代新型催化剂提供理论和实验基础。

Catalysis science still faces grand challenges of clearly identifying the nature of active sites, which severely hampers the designs at the molecule level and creation of new catalysts with desired proeprties. In this project, we aim to establish a Delta-XAFS method that is capable of seperating the structural information of active sites from the catalytically inactive atoms under operando conditions. This method is promising to achive a high detection sensivity of surface ative site that is as low as 5% among all absorbing atoms. Taking the low-temperature oxidization of CO as a model reaction system, the Delta-XAFS method will be applied to study the catalysis kinetics of supported metallic nanoclusters and oxides under operando conditions. By doing so, we are able to explore the structural and electronic properties of catalytically ative sites during the reactants’ adsorption, surface catalytic reactions and desorption of end products, as well as to identify the reaction intermediates and trace their fates. Other operando techeniques such as chromatography and infrered spetra will also be used to identify the transformations of regeants. Theoretical calculations will also be employed to enrich our understanding on the nature of active sites and to reveal the underlying catalytic mechanisms of meatllic nanocluster catalysts at the atomic/molecular level. All of these endeavors will be helpful for understanding the structure-activity-selectivity relationships of the nanocluster catalysts. The execution of project is promising to lay a solid foundation for further design and creation of next-generation novel catalysts.