Firmly adsorbed ammonia and pyridine species at activated kaolinite surfaces

Ahmet T., Beytullah A.

Adsorption Science and Technology, vol.19, no.8, pp.673-680, 2001 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 19 Issue: 8
  • Publication Date: 2001
  • Doi Number: 10.1260/0263617011494484
  • Journal Name: Adsorption Science and Technology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.673-680
  • Ondokuz Mayıs University Affiliated: Yes

Abstract

Acid activation increases the protonated species on a kaolinite surface at the expense of coordinately bound NH3 entities. The presence of NH+4 ions on an activated sample is not proof of the presence of protonic acid centres alone since the added proton may have come from the residual water in the interlayer. Progressive dehydration of the surface results in a strong increase in chemisorbed NH3. However, the 'ring frequency' region of coordinately bound pyridine (Py) and of the pyridinium ion (Py+) indicates that the strong acid sites on activated kaolinite are of the Lewis type.