新型催化材料Sr2FeMoO6的葡萄糖溶胶-凝胶法合成及甲烷催化燃烧性能

采用葡萄糖溶胶-凝胶法合成了Sr₂FeMoO₆催化剂，研究了空气、氩气和H₂/N₂ 3种焙烧气氛对产物的结构和性能的影响。运用X射线衍射（XRD）、程序升温还原（TPR）、傅里叶变换红外光谱（FT-IR）、比表面（BET）及磁性测量与甲烷催化燃烧活性评价等技术对所制备的样品进行了表征。XRD实验结果表明，H2/N2气氛下焙烧得到的样品是单相的双层钙钛矿结构氧化物Sr₂FeMoO₆，在氩气下焙烧的样品形成了主相为双层钙钛矿结构氧化物Sr₂FeMoO₆，同时伴有少量的SrMoO₄相，但在空气下焙烧的样品中除了Sr₂FeMoO₆的衍射峰，还出现了强度很高的SrMoO₄相的衍射峰。从TPR、FT-IR和磁性表征结果发现，不同的焙烧气氛所形成的样品程序升温还原图谱和红外光谱均有所差别，H₂/N₂气氛下合成的样品有较好的磁性，而氩气和空气下合成的样品的磁性几乎为零。对于H₂/N₂气氛下合成的单相Sr₂FeMoO₆样品的甲烷催化燃烧活性测试表明，甲烷燃烧起燃温度T₁₀为475℃，完全转换温度T₁₀₀为744℃，可见单相双层钙钛矿型结构化合物Sr₂FeMoO₆对甲烷催化燃烧也有很好的活性。

Preparation of novel catalyst Sr2FeMoO6 and its catalytic performance in methane combustion

The double perovskite catalyst Sr₂FeMoO₆ was prepared by the sol-gel method using glucose as complex agent, at 1100℃ for 3 h.The structure and performance of the catalyst prepared in various calcination atmospheres (H₂/N₂ mixed gas, argon, and air atmospheres) were investigated.The catalyst was characterized by means of X-ray diffraction (XRD), temperature programmed reduction (TPR), Fourier transform infrared spectroscopy (FT-IR)，specific surface area and magnetism techniques.Meanwhile the catalytic activity of double perovskite Sr₂FeMoO₆ in methane catalytic combustion was investigated.The XRD results indicated that single-phase double Sr₂FeMoO₆ was found in the catalyst, calcined in H₂/N₂ mixed gas.Double perovskite was the dominant phase, accompanied by a few scheelite-type SrMoO₄ in the catalyst calcined in argon atmosphere，whereas besides double perovskite phase a stronger SrMoO₄ phase was found in the catalyst calcined in air atmosphere.FT-IR and TPR results indicated that TPR spectrum and infrared spectroscopy of catalyst calcined in different atmospheres were different.The catalyst calcined in H₂/N₂ mixed gas had better magnetic property, whereas the catalyst calcined in argon and air atmospheres had little magnetism.The T₁₀(temperature for 10% methane conversion) and T₁₀₀(temperature for 100% methane conversion) of single-phase Sr₂FeMoO₆ double peroskite were 475℃and 744℃ respectively.So single-phase double perovskite Sr₂FeMoO₆ had good catalytic activity for methane catalytic combustion.