Study on In Situ Characterization of Metal-Support Interaction and Correlative Structure-Reactivity Relationship in Catalysis

不同尺寸和形态的氧化铈负载的IB金属（Au, Cu, Ag）纳米颗粒（NPs）由于对许多重要反应具有非凡的催化活性，已成为多相催化领域的研究热点之一。金属-载体强相互作用（SMSI）一直被认为是影响氧化物负载金属催化剂催化性能（活性、选择性和稳定性）的关键因素。尽管进行了广泛的研究，但对金属/铈催化剂的SMSI效应和构效关系的基本理解仍然缺乏，许多关键问题仍未得到解答。这主要是由于纳米结构金属/二氧化铈材料的复杂性和缺乏对定义良好的模型催化剂的彻底的表面科学研究。在这个联合项目中，两个合作小组将在金属/铈系统的制造和现场最先进的光谱和微观表征方面进行非常密切的合作。德国合作伙伴将对分散在单晶（偏振依赖的IRRAS）和纳米结构材料（红外透射）的二氧化铈表面上的IB金属（Cu, Ag, Au）簇进行全面的光谱（UHV-FTIRS与XPS和NEXAFS结合）研究。中国合作伙伴将专注于合成不同类型的具有可调谐尺寸和形状的金属/铈纳米颗粒。将进行相应的ETEM/ stem -纳米反应器实验，以成像各种金属/铈催化剂在活化和反应条件下的动态行为。此外，我们将对选择的反应机理和反应动力学，如低温CO氧化和水煤气转移反应，进行系统和协作的工作。我们的目标是在获得不同金属/氧化物单晶模型体系的可靠和全面的参考数据的基础上，对复杂的纳米结构金属/氧化物催化剂的结构、电子和反应性质进行详细的了解。总体目标是在原子水平上理解SMSI效应和固有的结构-反应性关系，从而能够在纳米尺度上预测、合理地设计基于二氧化铈的催化材料。

The study on ceria-supported IB metal (Au, Cu, Ag) nanoparticles (NPs) with different size and morphologies has become one of the most interesting topics in heterogeneous catalysis due to the extraordinary catalytic activities for many important reactions. The strong metal-support interaction (SMSI) has long been known to play a key role in the catalytic performance (activity, selectivity and stability) of oxide-supported metal catalysts. Despite extensive investigations, a fundamental understanding of the SMSI effect and the structure-activity relationship of metal/ceria catalysts is still lacking and many crucial issues remain unanswered. This is primarily due to the great complexity of nanostructured metal/ceria materials and the lack of a thorough surface science study on well-defined model catalysts. In this joint project, the two partner groups will work in a very close collaboration on fabrication and in-situ state-of-the-art spectroscopic and microscopic characterization of metal/ceria systems. The German partner will carry out a thorough spectroscopic (UHV-FTIRS in conjunction with XPS and NEXAFS) study on IB metal (Cu, Ag, Au) clusters dispersed on ceria surfaces of both single crystals (polarization-dependent IRRAS) and nanostructured materials (IR transmission). The Chinese partner will focus on the synthesis of different types of metal/ceria nanoparticles with tunable size and shape. The corresponding ETEM/STEM-Nanoreactor experiments will be conducted to image the dynamic behavior of various metal/ceria catalysts under activation and reaction conditions. In addition, we will do systematic and collaborative work on reaction mechanisms and reaction kinetics of selected reactions such as low-temperature CO oxidation and water gas shift reactions. We aim to achieve detailed insight into the structural, electronic and reactive properties of the complex nanostructured metal/oxide catalysts based on reliable and comprehensive reference data acquired for different metal/oxide monocrystal model systems. The overarching objective is an atomic-level understanding of the SMSI effect and the intrinsic structure-reactivity relationship, which enables the predictive, rational design of ceria-based catalytic materials at the nanoscale.