低温化学链CO2-CH4重整氧载体构建及界面调控

CO2-CH4重整是CO2规模化转化为化学品和燃料的重要手段。与共进料模式的直接重整相比，交替进料模式的化学链CO2-CH4重整工艺具有产物成分可控、避免积碳累积和突破热力学限制的优势。项目针对现有化学链CO2-CH4重整反应温度高及其带来材料烧结、副反应和能效低等问题，提出了构建新型储氧-催化双功能氧载体，开发400-600℃下的低温化学链CO2-CH4重整新工艺。围绕多碳源低温活化机制和储氧-催化耦合方法的关键科学问题，通过氧载体结构-Redox活性间的“构效关系”研究，探究氧载体制备过程中CeO2离子掺杂、Ni合金化、尺度/形貌效应、界面特征等对Redox活性的影响规律，获得铈基氧载体界面调控机制和可控制备方法；并结合原位表征手段和理论计算揭示Redox反应机理。项目的实施将拓展低温化学链应用领域，可促进CO2和CH4高效转化利用。

CO2-CH4 reforming is an important pathway for the largle-scale conversion of CO2 into chemicals and fuels. Compared to the CO2-CH4 reforming in a co-feeding mode, the chemical looping CO2-CH4 reforming scheme in an alternate feeding mode enables to control the composition of the syngas product, avoid the accumulation of the deposited carbon, and breakthrough the thermodynamic limits. While the state-of-art chemical looping CO2-CH4 reforming suffers from the high reaction temperatures that have caused serious sintering of the materials, side reactions, and low energy efficiencies. We proposed to synthesize a bifunctional oxygen carrier acting oxygen storage and catalytic roles to develop a novel low-temperature chemical looping CO2-CH4 reforming scheme at temperatures ranging from 400 to 600 ºC. The two key scientific issues are the mechanism of multiple carbon sources activation and the regulation of interfaces. The influencing rules of ion doping on CeO2, Ni alloying, scale/morphology effects, and interface properties of the oxygen carriers on the redox activity will be explored by the investigation of the structure-activity relationship between the oxygen carriers’ structure and the redox reactivity. Then we will obtain an interface regulation method and a controllable preparation method for the CeO2-based oxygen carriers. The redox mechanism will be also revealed by means of the in situ characterization and the theoretical calculation. The project will expand the low-temperature chemical looping applications and promote the effective conversion of CO2 and CH4.