中文摘要：

采用溶胶-凝胶法制备了不同B位可变价离子的LaMO3（M=Cr,Mn,Fe,Co）复合氧化物氧载体,采用X射线衍射、N2吸附-脱附、扫描电镜及CH4程序升温表面反应等手段对氧载体进行了表征,并用于直接选择氧化CH4的反应中.结果表明,Cr,Mn,Fe和Co均能形成LaMO3纳米复合钙钛矿结构,其氧物种氧化能力大小顺序为LaCoO3〉LaMnO3〉LaFeO3〉LaCrO3.在连续流动化学循环甲烷重整反应中,LaFeO3中的氧物种具有更好的选择氧化性能（H2/CO=2.06）,其CH4转化率和CO选择性分别达到89.6%和98.9%.10个连续顺序氧化-还原化学循环重整反应中,CH4转化率约为60%～70%,CO选择性达98%以上;且其结构保持了较高的稳定性.

英文摘要：

Catalytic reforming of natural gas is a commercial process to produce syngas,which is the main source for the production of am-monia,methanol,hydrogen,and many other important products.This method produces also large amounts of CO2 as by-product.Chemical-looping reforming（CLR）is a novel technology that can be used for syngas production by partial oxidation and steam reforming of hy-drocarbon fuels.One key issue with the CLR concept that is being widely studied is the oxidation and reduction behavior of potential oxygen-carrier materials.Four perovskite-based nano-composite oxides were prepared by the sol-gel method and characterized by X-ray diffraction,N2 adsorption-desorption,scanning electron microscopy（SEM）,and CH4 temperature-programmed surface reaction.The catalytic per-formance of the prepared samples for CLR of CH4 to syngas was investigated.The results showed that the LaMO3（B = Cr,Mn,Fe,and Co）oxides possess perovskite-type nano-composite structure.The oxidizing ability of these four perovskite oxides follows the order of LaCoO3 LaMnO3 LaFeO3 LaCrO3.Among them,LaFeO3 oxide has higher activity for CLR of CH4 to syngas.The CH4 conversion and CO selec-tivity are 89.6% and 98.9%,respectively.Especially,the sequential redox reaction revealed that the LaFeO3 oxide exhibits high stability with CH4 conversion of 60%～70% and CO selectivity of ～98% after 10 redox cycles.The SEM analysis revealed that the structure of the LaFeO3 oxide was not dramatically changed before and after 10 cyclic reactions.