【作者】 杨忠苹；

【导师】 胡瑞生；

【作者基本信息】 内蒙古大学 ， 物理化学， 2008， 硕士

【摘要】 采用以柠檬酸和葡萄糖为络合剂的溶胶-凝胶法制备了钙钛矿型复合氧化物LaSrBMnO₆（B=Fe、Co）、LaSrCoFeO₆；La_0．5Sr_0．5BO₃（B=Fe、Co、Mn）；La-B-Ti-O（B=Mg、Ca、Sr、Co）和La-Co-V-O、La₂CoMnO₆、La₂MnVO₆等四个系列的催化剂，运用XRD、TPR、FT-IR、BET、TEM、电导率和磁性等对其性质进行了表征，并考察了在甲烷燃烧反应中的催化性能。实验结果表明，在5H₂％／95％N₂气氛氛围中1100℃焙烧3h后，催化剂LaSrBMnO₆（B=Fe，Co）和LaSrCoFeO₆均生成了单相物相。其中，LaSrCoFeO₆对甲烷催化燃烧的起燃温度最低为460℃，完全转化温度为673℃；反应温度在500-650℃之间催化剂LaSrFeMnO₆对甲烷催化燃烧活性最好；催化剂LaSrCoMnO₆对甲烷燃烧催化活性最差。在室温下电导测试发现LaSrFeMnO₆的导电性最好，催化剂LaSrCoFeO₆的导电性最差。对几种单、双钙钛矿进行了化学与物理性能的比较，在三种催化剂LaSrCoFeO₆、La_0．5Sr_0．5CoO₃和La_0．5Sr_0．5FeO₃中，LaSrCoFeO₆对甲烷燃烧的催化活性最好，在测试温度范围内，LaSrCoFeO₆的导电性最差；在三种催化剂LaSrCoMnO₆、La_0．5Sr_0．5MnO₃和La_0．5Sr_0．5CoO₃中，La_0．5Sr_0．5MnO₃对甲烷燃烧的催化活性最好，在测试温度范围内其导电性也最好；在三种催化剂LaSrFeMnO₆、La_0．5Sr_0．5MnO₃和La_0．5Sr_0．5FeO₃中，La_0．5Sr_0．5MnO₃对甲烷燃烧的催化活性最好，在测试温度范围内，催化剂LaSrFeMnO₆的导电性最好。采用柠檬酸作络合剂的溶胶-凝胶法制备的三种催化剂La₂CoMnO₆、La₂MnVO₆和La-Co-V-O，在5H₂％／95％N₂气氛氛围中1100℃焙烧3h后制备单相双钙钛矿型催化剂La₂CoMnO₆和La₂MnVO₆，而体系La-Co-V-O没有得到单相物相。同时，对比两种催化剂LaSrCoMnO₆和La₂CoMnO₆对甲烷催化燃烧的活性及其磁性。以葡萄糖作络合剂的溶胶-凝胶法制备催化剂La-B-Ti-O（B=Mg、Ca、Sr、Co），在空气中1100℃焙烧3h后制备出单相双钙钛矿型催化剂La₂MgTiO₆，其它三种催化剂La-B-Ti-O（B=Ca、Sr、Co）没有得到单相物相。对催化剂La₂MgTiO₆进行不同焙烧温度的结构和性能比较，发现在500℃焙烧3h后即制得单相催化剂La₂MgTiO₆；而在800℃焙烧3h后，催化剂La₂MgTiO₆对甲烷催化燃烧活性最好。更多还原

【Abstract】 The perovskite-type composite oxide LaSrBMnO₆（B=Fe、Co） ,LaSrCoFeO₆;La_0.5Sr_0.5BO₃（B=Fe、Co、Mn）; La-B-Ti-O（B=Mg、Ca、Sr、Co） and La-Co-V-O、La₂CoMnO₆、La₂MnVO₆ were synthesized by the sol-gel method and characterized by means of XRD、TPR、BET、FT-IR、TEM、the catalytic activity evaluation、conductivity and magnetic properties.We find that the single-phase perovskite-type oxides LaSrBMnO₆（B=Fe,Co）, LaSrCoFeO₆ and La_0.5Sr_0.5BO₃（B=Fe,Co,Mn） were synthesized by the sol-gel using citric acid as complex agent. It is shown that LaSrFeMnO₆ showed a higher conductivity than LaSrCoMnO₆ and LaSrCoFeO₆ after 1100℃calcinations for 3h in 5H₂%/95%N₂. LaSrCoFeO₆ showed a better catalytic activity for methane combustion than LaSrBMnO₆（B=Fe,Co）, which T₁₀（methane conversion of 10%） and T₉₀（methane conversion of 90 % ） were 460℃and 673℃respectively, and LaSrFeMnO₆ showed the best catalytic activity between 500-650℃.The chemical and physical properties of several of the single, double perovskite-type oxides were compared under the same condition. In the first group, LaSrCoFeO₆, La_0.5Sr_0.5CoO₃and La₍0.5_Sr_0.5FeO₃, LaSrCoFeO₆ had the best catalytic activity for methane combustion but the worst conductivity. In the second group, LaSrCoMnO₆, La_0.5Sr_0.5MnO₃ and La_0.5Sr_0.5CoO₃, La_0.5Sr_0.5MnO₃ had the best catalytic activity and conductivity. In the third group, LaSrFeMnO₆,La_0.5Sr_0.5MnO₃ and La_0.5Sr_0.5FeO₃, La_0.5Sr_0.5MnO₃ had the best catalytic activity and LaSrFeMnO₆ had the best conductivity.The La₂CoMnO₆, La₂MnVO₆ and La-Co-V-O were prepared by the sol-gel using citric acid as complex agent. The studies showed that single-phase perovskite-type oxides La₂CoMnO₆ and La₂MnVO₆ were synthesidzed after 1100℃calcinations for 3h in 5H₂%/95%N₂, but the system of La-Co-V-O was not synthesized single-phase. Meanwhile, we also compared catalytic activity for methane combustion and magnetic activity of LaSrCoMnO₆ and La₂CoMnO₆.Four systems of perovskite-type composite oxides La-B-Ti-O（B=Mg,Ca,Sr,Co） were prepared by sol-gel using glucose as complex agent. Experimental results show that La-B-Ti-O（B=Ca、Sr、Co） were not synthesized single-phase perovskite-type oxides and the La₂MgTiO₆ was synthesized after 500℃calcinations for 3h in the air. The catalytic activity of La₂MgTiO₆ was the best after 800℃calcinations for 3h in the air.更多还原