氧化亚氮（N2O）作为一种温室气体越来越受到关注。直接催化分解N2O具有工艺简单、经济高效、无二次污染等优点，在化工生产、生物质燃烧、机动车尾气处理等领域具有良好的应用前景。轻稀土元素由于具有大离子半径、非半满4f和空5d电子轨道等特殊的本征性质，其作为助剂或主催化组分在多相催化领域有着广泛研究。本论文考察轻稀土作为助剂和载体，旨在开发低温高性能、高温高稳定性的轻稀土基N2O分解催化剂，并从几何和电子结构层面探究催化剂在N2O分解反应过程中的构效关系，探究反应机制，为实现N2O分解催化剂工业化应用提供理论依据。本论文探究了富4f电子轻稀土钐（Sm）和镨（Pr）的掺杂效应对Co3O4活性位点几何和电子结构的调控，对催化剂低温催化N2O分解性能的影响。制备的一种新型的Sm掺杂Co3O4催化剂具有高效的低温N2O分解活性。Sm掺杂有效促进氧空位产生，为N2O分子提供充足的吸附与活化位点。Co和Sm物种的电子相互作用形成的Co3++Sm2+?Co2++Sm3+氧化还原循环是Sm掺杂实现N2O高效分解的主要原因。明确了Sm作为结构助剂。合成的单原子Pr限域的Co3O4催化剂拥有优异的低温N2O分解性能和高O2/NOx/H2O耐受性。单原子Pr掺杂诱导产生的“Pr 4f–O 2p–Co 3d”杂化轨道网络触发4f?3d电子梯的形成，加速了电子从Co2+到N2O的3π*反键轨道转移，从而有助于N?O键的断裂。确定了Pr为电子助剂。本论文进一步考察了缺4f电子轻稀土CeO2的载体效应。CeO2担载的具有低配位数的单原子铑（Rh）催化剂，具有N2O和一氧化碳（CO）低温高效协同脱除性能，并揭示了以Rh–O–Ce界面位点为反应活性中心的催化机制。“金属—载体强相互作用”促使Rh向Ce位点传输电子，进而诱导N–O键断裂。此外，N2O分解过程对电子的消耗促进了CO与Rh位点的电子传输，从而活化了C≡O；通过CO氧化消耗N2O在分解过程中产生的活性氧物种，从而加速N2O分解进程。制备了具有优异高温稳定性的负载型Zn掺杂Co3O4/CeO2催化剂。Zn掺杂形成的Co2–xZnxO4尖晶石活性相增强了负载组分与载体间的界面电子相互作用，使得负载组分更具富电子性，从而有助于N2O分子的活化分解。同时证明N?O键活化为反应决速步骤而非O2脱附过程。

Nitrous oxide (N2O), as an important non-carbon dioxide greenhouse gas, is receiving increasing attention. The technology of direct catalytic N2O decomposition has the advantages of simple craft, economic efficiency, no secondary pollution, and good application prospects in chemical production, biomass combustion, and vehicle exhaust treatment fields. The light rare earth elements (LREEs) have been widely studied in the field of heterogeneous catalysis as promoters or active components due to their special intrinsic properties such as large ionic radius, below half-filled 4f and empty 5d electronic orbitals. Hence, this thesis investigates the LREEs as promoters and supports, aiming to develop light rare earth-based N2O decomposition catalysts. Additionally, the structure-activity relationship of catalysts in the N2O decomposition process is explored from the perspective of geometric and electronic structure regulation, so as to clarify the reaction mechanism, and to provide theoretical reference for industrial application. The innovative achievements are as follows:The doping effect of 4f electron rich LREEs samarium (Sm) and praseodymium (Pr) on the geometry and electronic structure of the active sites of Co3O4 was investigated in this thesis, as well as its further influence on the catalytic N2O decomposition performance at low temperature. A novel samarium (Sm) doped Co3O4 catalyst was prepared, which demonstrates high efficiency of low-temperature N2O decomposition activity. The results displayed that Sm-doping effectively promotes the generation of oxygen vacancies, thus providing sufficient adsorption and activation sites for N2O molecules. The redox cycle of Co3++Sm2+?Co2++Sm3+ formed by electronic interactions between Co and Sm species is the main reason for the efficient N2O decomposition through Sm doping. It was clearly defined that Sm is a structure promoter. The successfully synthesized single-atom praseodymium (Pr) confined Co3O4 catalyst exhibits excellent low-temperature N2O decomposition performance and high O2/NOx/H2O durability. It was found that the single-atom Pr doping induced the formation of a "Pr 4f–O 2p–Co 3d" network, which triggered the formation of 4f?3d “electron ladder”, and accelerated the transfer of electrons from Co2+ to the N2O 3π* antibonding orbital, thus contributing to the breaking of N?O bonds. Pr has been determined as an electronic assistant.This thesis further explores the support effect of poor 4f electron light rare-earth ceria (CeO2). A CeO2 supported single-atom rhodium (Rh) catalyst with low coordination number has been developed, which shows high efficiency of N2O and CO co-removal at ultra-low temperature. It was revealed that the Rh–O–Ce interface site is the reaction active center. The results attested that the strong metal-support interaction between Rh and Ce triggers the formation of the “Rh 4d–O 2p–Ce 4f” electron orbitals network, which leads to the transportation of electrons from Rh to the Ce site because of potential difference, further inducing N–O bond breakage. In addition, the decomposition process of N2O promotes electron transport between CO and Rh sites, thereby activating the carbon-oxygen triple bond, while the process of N2O decomposition is accelerated by consuming reactive oxygen species produced in this process via CO oxidation. The prepared supported Zn-doped Co3O4/CeO2 catalyst exhibits excellent high-temperature stability. It was found that the active phase of Co2-xZnxO4 spinel formed by Zn-doping enhances the interfacial electronic interaction between the loaded component and the carrier, making the loaded component more electron rich, thereby facilitating the activation and cracking of N2O molecules. Meanwhile, it is demonstrated that the activation of the N–O bond is a reaction rate determining step rather than an O2 desorption process.