高等学校化学学报

高等学校化学学报 ›› 1996, Vol. 17 ›› Issue (10): 1617.

• 论文 • 上一篇    下一篇

掺杂钛酸盐对乙烷氧化脱氢催化性能的研究

陈铜1, 李文钊1, 于春英1, 季亚英1, 于作龙2   

  1. 1. 中国科学院大连化学物理研究所, 大连, 116023;
    2. 中国科学院成都有机化学研究所
  • 收稿日期:1995-09-05 出版日期:1996-10-24 发布日期:1996-10-24
  • 通讯作者: 李文钊
  • 作者简介:陈铜,男,34岁,博士研究生.
  • 基金资助:

    国家自然科学基金

Catalytic Behavior for Oxidative Dehydrogenation of Ethane over Doped MTiO3 Catalysts

CHEN Tong1, LI Wen-Zhao1, YU Chun-Ying1, JI Ya-Ying1, YU Zuo-Long2   

  1. 1. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023;
    2. Chengdu Institute of Organic Chemistry, Academy of Science, Chengdu, 610041
  • Received:1995-09-05 Online:1996-10-24 Published:1996-10-24

PDF (PC)

被引次数

10

摘要： 在700～850℃范围内研究了掺杂CaTiO3、SrTiO3催化剂用于乙烷氧化脱氢(ODHE)的催化行为。发现这类催化剂对ODHE均有一定的催化活性。适量的Li+取代Ti4+后不仅提高了催化活性,而且改善了催化剂对乙烯的选择性。催化剂CaTi0.9Li0.1O3-δ在850℃时乙烷转化率和乙烯选择性分别为87.8%和71.7%.Sr对Ca部分取代后制得的催化剂可在极宽的温度范围内(700～850℃)保持较高的乙烯选择性(≥90%).讨论了低价Li+取代高价Ti4+后在催化剂晶格中形成氧空位进而生成非完全还原氧,发现该氧物种与乙烯选择关联很好。低空速有利于乙烷的低温转化,高空速则有利于乙烯的选择性,尤其是高温选择性。催化剂中的碱土金属离子易与CO2作用生成碳酸盐等,阻碍了反应物与催化剂表面活性中心的作用,当温度升高后碳酸盐分解放出CO2时,催化剂才表现出原来应有的活性。

关键词: 乙烷, 氧化脱氢, 掺杂钙钛矿型复合氧化物

Abstract: The catalytic behavior of the various doped-MTiO3(M=Ca,Sr) catalysts for the oxidative dehydrogenation of ethane(ODHE) was examined in the temperature range of 700 ～850℃.All of the catalysts have certainly shown a catalytic activity for ODHE.When Li+substituted Ti4+ in CaTiO3,a much better improvement in the C2H4 selectivity was observed.Selectivity 71.7% for C2H4,and conversion 87.8% for C2H6 could be obtained over the catalyst,CaTi0.9Li0.1O3-δ at 850℃.The substitution of Sr for Ca in Ca1-xSrxTi0.9Li0.1O3-δ could give a high selecitivity(≥90%) for C2H4 in a very widely temperature range(700～850℃).The effect of Li+ doping was explained by the increment of oxygen vacancy and the formation of non-fully reduced oxygen species.The non-fully reduced oxygen species are suggested as the active sites responsible for ethylene selecivity,and the reaction between reactants and catalyst is inhibited by CO2.

Key words: Ethane, Oxidative dehydrogenation, Mixed oxide of the doped perovskite

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