化学循环干气重整（CLDR）可同时实现含碳燃料的高效利用、CO2的廉价捕集和定向转化。决定CLDR系统运转的关键是氧载体（实质是氧化还原催化剂），它不仅要能够为燃料提供氧，其还原态还要能够从低化学势的CO2中捕获氧。开发具有高氧化还原活性、强氧传输扩散能力和优异高温稳定性的氧载体以及研究其CLDR作用机制是目前亟需解决的问题。本申请以具有高活性、高温稳定性的Fe基六铝酸盐为前体，通过大阳离子种类和过渡/贵金属离子取代实现氧载体微观结构、氧化还原活性、氧移动性的调控，获得高效CLDR用氧载体。综合利用多种表征技术确定氧载体在CLDR反应过程中的微观结构和化学状态(晶位分布、配位情况、电子状态等)变化规律，结合密度泛函理论计算，研究其作用机制，力图从微观结构、化学状态、氧移动能力多角度揭示Fe基六铝酸盐氧载体在CLDR反应过程中的催化本质，为高效CLDR用氧载体的研究和开发提供理论和实验依据。

Chemical looping dry reforming (CLDR) opens a novel pathway to high-efficient utilization of carbon-based fuel, CO2 capture and activation, simultaneously. CLDR uses periodic reduction and oxidation of an oxygen carrier with carbon-based fuel and CO2, respectively, to achieve sequestration-ready CO2 streams and CO, respectively. Oxygen carrier (red-ox catalyst in essence) is the key factor, which dominates the feasibility of CLDR process. Now, It is indispensable to develop a highly red-ox active, high oxygen mobility and high-temperature stable oxygen carrier and to establish the relationship between the structure and reaction performances of CLDR. In this application, we will select Fe-based hexaaluminate to prepare CLDR oxygen carrier, which combined highly red-ox active and remarkable resistance to sintering and thermal shock due to its peculiar layered structure. Furthermore, we will adjust the type and proportion of large cations and the substituted transition/noble metal ions in Fe-based hexaaluminate structure to modify its micro-structure, red-ox active, and oxygen mobility, in order to obtain novel high- efficient CLDR oxygen carrier. After that, the relationship between structure and reaction performance of CLDR will be established. Through characterization technologies (eg. XRD, FTIR, TGA, Rietveld refinement, 57Fe M?ssbauer spectroscopy), we will discuss the variation of micro-structure and chemical state (the crystallographic site distribution, the coordination, and electronic status) of oxygen carrier in the CLDR reaction process, which was then used to explore the catalytic mechanism combined with the DFT calculation. The aim of this application is to understand the catalytic essence of Fe-based hexaaluminate oxygen carriers in the CLDR system in the view of micro-structure, red-ox active, and mobility of lattice oxygen, and then provide technical and theoretical guide for developing novel high- efficiency CLDR oxygen carriers.