摘要
采用燃烧法合成大比表面钙钛矿型复合氧化物多孔材料LaCoO3和La0.95Sr0.05Ni0.05Co0.95O3,通过XRD、IR和BET技术考察了多孔材料的晶体结构、表面形态结构、比表面积、平均孔径和平均孔体积。结果表明,采用燃烧法合成的多孔材料归属于钙钛矿型复合氧化物。对于La-CoO3化合物,A位掺杂的Sr2+和B位掺杂的Ni2+均进入了晶格,分别取代晶格内相应位置上的La3+和Co2+。但La0.95Sr0.05Ni0.05Co0.95O3的XRD图谱峰强度降低、衍射峰变宽。样品粉体的吸附脱附等温线存在一明显的滞后环,表明样品为多孔材料。掺杂样品材料的平均孔径、比表面积和平均孔容等性能参数比未掺杂的样品均有改善。甲烷催化燃烧实验表明,样品具有良好的催化活性。
Perovskite-type complex oxides LaCoO3 and La0.95Sr0.05Ni0.05Co0.95O3 with large surface were prepared by combustion method.The properties of porous materials such as crystal structures,particle sizes,surface patterns,pore size,surface area and pore volume were characterized by XRD,SEM and BET methods. The result indicated that all porous materials were the perovskite-type complex oxides. For LaCoO3 compound,Sr2+ ions on site A and Ni2+ ions on site B were doped into the crystal lattices of LaCoO3 and took the place of La3+ and Co2+ But for La0.95Sr0.05Ni0.05Co0.95O3, the peak intensity was weaken and the diffraction maximum was broaden at XRD atlas. The surface appearance of sample powder showed synusia and porous structure and its layers decreased after doping. Hysteresis loop in the N2 adsorption-desorption isotherm indicated the samples had porous structure.The pore size, surface area and pore volume of doped samples were better than those of non-doped samples.The samples have been tested for methane catalytic combustion and the results showed that these catalysts had high catalytic activity.
出处
《石油与天然气化工》
CAS
CSCD
北大核心
2007年第4期269-270,281,共3页
Chemical engineering of oil & gas
基金
高等学校博士学科点专项研究基金(20040403001)
关键词
燃烧法
钙钛矿复合氧化物
大比表面
甲烷燃烧
催化剂
combustion method, perovskite-type complex oxides, large surface, combustion of methane
