钙钛矿型化合物催化氧化性能与d电子构型关系的研究 |
| |
引用本文: | 秦永宁,田辉平,张鎏.钙钛矿型化合物催化氧化性能与d电子构型关系的研究[J].化学学报,1993,51(4):319-324. |
| |
作者姓名: | 秦永宁 田辉平 张鎏 |
| |
作者单位: | 天津大学化工系,天津大学化工系,天津大学化工系 天津 300072,天津 300072,天津 300072 |
| |
摘 要: | 我们用活性评价、磁性测定、原子吸收光谱、TPR(程序升温还原)、TPSR(程序升温表面反应)、XRD等手段研究了以共沉淀和混合法制备的LaMO2(M为从钛到铜的八个过渡金属离子)钙钛矿型化合物对CH4和CO的催化氧化性能。结果表明, 随M离子的d电子数增多, 催化剂的催化氧化活性呈现三峰变化模式并与表面氧结合能及TPSR活性氧物种分布规律一致。根据磁性分析了M离子d电子组态, 对活性的三峰现象作了说明。比较了不同方法对催化剂上氧物种的表征效果。考察了在氧化还原气氛下M离子价态变化规律。根据实验结果讨论了催化剂上活性氧物种分布。
|
关 键 词: | 原子吸收分光光度法 X射线衍射分析 甲烷 电子结构 催化氧化 氧化碳 程序升温还原 程序升温表面反应 钙钛矿型化合物 |
Study on the correlation of d-electron configuration and catalytic oxidation activity of LaMO3 compounds |
| |
Abstract: | The catalytic activity for CH4 and CO oxidation of LaMOs (M is transition metal ion) perovskite-type oxide prepared by copptn. and mixing methods has been studied by activity evaluation, magnetic measurement, element anal., TPR, magnetic measurement, an explaination has been put up to the results which show a tri-peak pattern for 3d-electron no. vs catalytic activity. Proportional relations have been found between catalytic activity and either surface oxygen bonding energy or TPSR active oxygen content in LaMO3 compounds The valence of M ions in for Ti and V, n > 3; for Cr, n ?3; for the others, n < 3. The active oxygen distribution in the series oxides has been discussed. |
| |
Keywords: | ATOMIC ABSORPTION SPECTROPHOTOMETRY X-RAY DIFFRACTION ANALYSIS METHANE ELECTRONIC STRUCTURE CATALYTIC OXIDATION CARBON OXIDE TEMPERATURE PROGRAMMED REDUCTION TEMPERATURE PROGRAMMING SURFACE REACTION |
本文献已被 CNKI 维普 等数据库收录! |
| 点击此处可从《化学学报》浏览原始摘要信息 |
| 点击此处可从《化学学报》下载免费的PDF全文 |
|