Subscribe Now Subscribe Today
Science Alert
 
Blue
   
Curve Top
Research Journal of Environmental Sciences
  Year: 2007 | Volume: 1 | Issue: 2 | Page No.: 64-70
DOI: 10.3923/rjes.2007.64.70
 
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail

Change in Surface Acidity of Nano-Ball Allophane upon Zinc Adsorption and its Mechanisms

Adel Ghoneim, Naoto Matsue, Azza Ebid and Teruo Henmi

Abstract:
Effect of zinc adsorption on the change in surface acidity of two nano-ball allophane samples with varying Si/Al ratio was studied. Zinc adsorption caused the enhancement in the surface acidity of nano-ball allophane samples. The enhancement in the surface acidity after zinc species adsorption is attributed to the inductive effect on the Si–OH groups near the adsorption sites. Molecular orbital calculations indicated that Zn2+ ion has the possibility to accelerate deprotonation of the Si–OH functional groups near the adsorption site. The result showed that the surface acidity of the allophane sample with a higher Si/Al ratio (KnP) was stronger than the KyP sample with lower Si/Al ratio. This tendency was observed under RH between 0 and 76%; then, the acid strength for the two nano-ball samples was the same at RH of 100%. The stronger acidity of the KnP sample is attributed to its a higher number of accessory polymeric silanol groups attached to the main frame structure, which cause the enhancement of the Brønsted acidity. The higher increase in the acid strength of the KnP could be also attributed to its higher adsorptive capacity for zinc species.
PDF Fulltext XML References Citation Report Citation
 RELATED ARTICLES:
  •    Indonesian Montmorillonite-supported ZnO: Preparation, Characterization and Activity Test in Methanol Dehydration
How to cite this article:

Adel Ghoneim, Naoto Matsue, Azza Ebid and Teruo Henmi, 2007. Change in Surface Acidity of Nano-Ball Allophane upon Zinc Adsorption and its Mechanisms. Research Journal of Environmental Sciences, 1: 64-70.

DOI: 10.3923/rjes.2007.64.70

URL: https://scialert.net/abstract/?doi=rjes.2007.64.70

COMMENT ON THIS PAPER
 
 
 

 

 
 
 
 
 
 
 
 
 

 
 
 
 
 
 

Curve Bottom