物理化学学报 >> 1995, Vol. 11 >> Issue (04): 337-341.doi: 10.3866/PKU.WHXB19950410

研究论文 上一篇    下一篇

ZrO2酸碱性质的TPD表征 III.苯酚和CO2或NH3共吸附

徐柏庆,山口力   

  1. 大连理工大学化工学院化学系|大连 116012|日本爱媛大学工学部应用化学系|松山 790
  • 收稿日期:1994-04-27 修回日期:1994-09-27 发布日期:1995-04-15
  • 通讯作者: 徐柏庆

Characterization of Acid-base Property of ZrO2 by Thermal Desorption:III.Dual Adsorption of Phenol and NH3 or CO2

Xu Bo-Qing,Yamaguchi Tsutomu   

  1. Department of Chemistry,School of Chencal Engineering,Dalian University of Technology,Dalian 116023|Department of Applied chemistry,Faculty of Enginering,Ehime University,Matsuyama 790,Japan
  • Received:1994-04-27 Revised:1994-09-27 Published:1995-04-15
  • Contact: Xu Bo-Qing

摘要:

用TPD-MS技术对ZrO2上PhOH和CO2或NH3双组分共吸附效应进行了研究.当有CO2或NH3预先吸附时,PhOH的吸附状态和脱附温度并不发生改变.PhOH一方面可以取代与表面酸-碱对中心有关的强吸附CO2或NH3物种而吸附,另一方面表面剩余的CO2或NH3吸附物种又能通过表面键诱导极化使一些“潜在的酸碱中心”得到活化,组成能够吸附PhOH的酸-碱对中心.后一种作用可导致PhOH吸附量增加一倍,表明ZrO2表面具有很高的可极化度.

关键词: 氧化锆, 酸-碱作用, 表面键诱导作用, TPD, 苯酚

Abstract:

 In the present study phenol has been used to show the pre-adsorption effects of NH3 or CO2 on the acid-base property of ZrO2 by TPD and IR measurements. It is shown that the pre-adsorption of either NH3 or CO2 results in a large increasement of phenol adsorption, almost twice that of phenol single adsorption, on the surface. However, the pre-adsorptions hardly change the adsorption state and the adsorption behavior of phenol. On the other hand the main part of the more strongly adsorbed NH3 or CO2 is easily replaced by the post-adsorption of phenol. These observations suggest a high polarizability of the ZrO2 surface, and can be discussed in terms of the surface induced through-bond acid-base interaction. It is proposed that there exists some “latent acid and base sites” which are activable with the adsorption of NH3 and CO2. These sites when being activated can participate in the formation of phenol-adsorbing acid-base pair sites.

Key words: Zirconium dioxide, Acid-base interaction, Surface induced interaction, Phenol, TPD, CO2, NH3