Acta Phys. -Chim. Sin. ›› 1995, Vol. 11 ›› Issue (04): 337-341.doi: 10.3866/PKU.WHXB19950410

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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

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