中华医学超声杂志

应用化学 ›› 1991, Vol. 0 ›› Issue (3): 60-62.

• 研究简报 • 上一篇    下一篇

Li/La2O3的表面活性氧及其在甲烷氧化偶联中的催化行为

王吉祥, 刘艳滨, 王连驰, 吴越   

  1. 中国科学院长春应用化学研究所, 长春 130022
  • 收稿日期:1990-02-16 修回日期:1990-06-09 出版日期:1991-06-10 发布日期:1991-06-10
  • 基金资助:
    国家自然科学基金

THE ACTIVE OXYGEN ON Li/La2 O3 SURFACE AND ITS CATALYTIC BEHAVIOR IN OXIDATIVE COUPLING OF METHANE

Wang Jixiang, Liu Yanbin, Wang Lianchi, Wu Yue   

  1. Changchun Institute of Applied Chemistry, Academia, Sinica, Changchun 130022
  • Received:1990-02-16 Revised:1990-06-09 Published:1991-06-10 Online:1991-06-10

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摘要： 甲烷氧化偶联反应近年来研究十分活跃[1-3]。Lunsford等[4-6]报道了载有碱金属的碱土氧化物是对此反应有效的催化剂,并提出晶格取代型活性中心[M+O-]和表面活化、气相偶联的反应机理。Otsuka等[7]系统地研究了稀土氧化物的甲烷氧化偶联活性,本文通过氧化镧中添加锂前后的对比,运用骤冷技术与ESR法研究了催化剂的表面活性氧,以低温TPD法研究了甲烷在催化剂表面上的吸附与活化,以及在甲烷氧化偶联中的催化行为。

关键词: 甲烷, 氧化偶联, 氧化镧, 锂, 表面活性氧

Abstract: The selectivity of oxidative coupling of methane was greatly enhanced by adding Li toLa2O3.By using quenching and ESR technique, O2- species were found on Li/La2O3, butnot on the single La2O3.TPD measurements from 77K to room temperature were performedon methane preadsorbed on Li/La2O3 and single La2O3.Ethane desorbed during theTPD of Li/La2O3, but could not be detected in that of single La2O3.It is considered thatthe addition of Li to La2O3 gives rise to some basic sites, which are favorable to the coup-ling reaction, and this addition decreases the surface area, resulting in repression of thefurther oxidation of CH3.radicals.

Key words: methane, oxidative coupling, lanthanum oxide, lithium, active oxygen

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