物理化学学报 >> 1997, Vol. 13 >> Issue (04): 344-350.doi: 10.3866/PKU.WHXB19970411

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含Cu复合氧化物对NO和CO吸附和活化的TPSR研究

赵震,杨向光,吴越   

  1. 中国科学院长春应用化学研究所，长春 130022
  • 收稿日期:1996-08-26 修回日期:1997-01-06 发布日期:1997-04-15

Study on the Adsorption and Activation of NO and CO over Mixed Oxide Catalysts Containing Cu by Means of TPSR

Zhao Zhen,Yang Xiang-Guang,Wu Yue   

  1. Changchun Institute of Applied Chemistry,Academia Sinica,Changchun 130022
  • Received:1996-08-26 Revised:1997-01-06 Published:1997-04-15

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摘要：

利用MS－TPD法并结合XRD、化学分析等对催化剂进行了表征，探讨了K2NiF4结构La2-x(Sr，Th)xCuO4±λ系催化剂中三个典型样品LaSrCuO4、La2CuO4和La1.7Th0.3CuO4对NO、CO及CO＋NO等小分子的吸附性能和活化规律. 结果表明：NO吸附量的大小与催化剂中氧空位含量有关，吸附强度和脱附峰种类与金属离子氧化态有关. CO在氧缺陷复合氧化物催化剂上的吸附是首先变为碳酸根，并在高温以CO2物种脱出. 在NO和CO的共吸附过程中，有关NO的吸、脱性能与单独NO－TPD中NO的吸脱附规律相似，表明NO在NO＋CO共吸附的竞争吸附过程中，优先吸附起决定作用，而受CO的影响较小. NO的吸附是NO活化分解的必要条件.

关键词: K2NiF4型复合氧化物, MS-TPD法, NO、CO和CO+NO的吸附

Abstract:

Adsorption and activation of small molecules NO, CO and CO+ NO on LaSrCuO4,La2CuO4 and La1.7Th0.3CuO4 which are typical samples in the sence of nonstoichiometric oxygen(λ) anrong the series of La2-x(SrTh)xCuO4±λ mixed oxide catalysts were studied by means of MS- TPD (TPSR ), XRD, chemical analysis and so on. It was shown that the adsorption amount of NO can be correlated with the content of oxygen vacancy while the types and strength of adsorption of NO could be related to the oxidation state of the metallic ion. It was also found that CO molecule was first converted into CO32- and then desorbed in the form of CO2 at high temperature during the adsorption and desorption of CO on the mixed oxide with oxygen vacancy. The fact that the profiles of TPD(TPSR) of NO in co-adsorption of NO+CO and in single NO adsorption are similar shows that the adsorption of NO molecule not only has some priority to that of CO but also is stronger than that of CO. It seems that the adsorption of NO plays a dominate role in the activation and decomposition of NO.

Key words: Adsorption of NO、CO and CO+NO molecules, Mixed oxides with K2NiF4 structure, MS-TPD