中华医学超声杂志

应用化学 ›› 1993, Vol. 0 ›› Issue (2): 51-56.

• 研究论文 • 上一篇    下一篇

甲烷氧化偶联La-Mn-Li系复合氧化物催化剂的研究

远松月, 李景虹, 于作龙   

  1. 中国科学院长春应用化学研究所 130022 长春
  • 收稿日期:1992-04-07 修回日期:1992-12-21 出版日期:1993-04-10 发布日期:1993-04-10

STUDIES OF THE La-Mn-Li MIXED OXIDE CATALYSTS FOR OXIDATIVE COUPLING OF METHANE

Yuan Songyue, Li Jinghong, Yu Zuolong   

  1. Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022 Changchun
  • Received:1992-04-07 Revised:1992-12-21 Published:1993-04-10 Online:1993-04-10

PDF

358

被引次数

1

摘要： 用XRD、IR、XPS和SEM等方法研究了混合氧化物LiLa1-xMnxO2的结构和它们对甲烷氧化偶联的催化性能。结果表明,随着MnO2的变化,可形成一系列复合氧化物,其中三元复合氧化物La2Mn1-yLiyO4是甲烷氧化偶联的活性相,由于Li+部分取代Mn2+形成Li+-O--Mn(2+)缺陷簇,增加了活性氧种的浓度和再生速度是这种氧化物具有较高甲烷偶联活性的主要原因。脉冲实验证明,CH4脱氢生成CH3·偶联生成C2H6,进一步氧化脱氢生成C2H4都可在催化剂表面完成,而CO和CO2是在气相反应中生成的。在780℃ C2收率可达23.9%。

关键词: La-Mn-Li复合氧化物, 催化, 氧化偶联, 甲烷

Abstract: The structures and the catalytic properties of mixed oxides, LiLa1-xMnxO2, have been studied by means of XRD, IR, XPS and SEM. The effects of reaction conditions were examined. The results showed that a series complex oxides could be formed at different X values. The ternary complex oxides La2Mn1-yLiyO4 were found to be the active phase for the oxidative coupling of methane, in which the defect cluster Li+-O--Mn2+ was formed as a result of the substitution of part Li+ for Mn2+ in La2MnO4. That increased the concentration of active oxygen species O- and enhanced its regeneration rate. It was the premiere factor of the complex oxide to possess a higher catalytic activity. The pulse reaction results showed that all the reations:CH4→CH3 ·2CH3·→C2H6, and C2H6→C2H4 could take place on the catalyst surface, while the CO2 was only formed in the gas phase. A higher C2 yield of 23.9% was obtained at 780℃.

Key words: methane, La-Mn-Li complex oxide, catatytic, oxidative coupling

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