Abstract

he surface and acidic properties of mixed sulfated zirconium and titanium oxides were investigated in the present study. One mode of preparation was followed entailing the use of zirconium sulfate and titanium oxysulfate as starting materials in a 1:1 ratio, and ammonium hydroxide as a precipitating agent. The resulting oxides were subjected to different extents of washing with water to vary their sulfate content. The mixed oxides were then analyzed by nitrogen adsorption, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis, and elemental analysis for sulfur content. The number of acidic sites was determined from the saturation values of the adsorption isotherms of sodium hydroxide. The presence of sulfate groups is found to be the crucial parameter in generating acidity in the mixed zirconium and titanium oxides. A striking feature observed in the present work is the significant increase in acidity in conjunction with the appearance of chelated sulfato ligands in the oxides. Textural analysis of the nitrogen adsorption isotherms and as plots reveal a predominance of a mixture of micropores and mesopores. Observed extents of surface areas do not directly correlate with the surface acidic properties. Sulfate groups appear to have a pore blocking effect leading to drastic decreases in surface areas.

Department

Physics Department

Degree Name

MS in Physics

Date of Award

2-1-2006

Online Submission Date

1-1-2005

First Advisor

Jehane Ragai

Second Advisor

Adham Ramadan

Committee Member 1

Hosny Omar

Committee Member 2

Suzy Selim

Committee Member 3

Amr Shaarawi

Document Type

Thesis

Extent

72 leaves :

Library of Congress Subject Heading 1

Titanium group.

Library of Congress Subject Heading 2

Zirconyl sulfate.

Rights

The American University in Cairo grants authors of theses and dissertations a maximum embargo period of two years from the date of submission, upon request. After the embargo elapses, these documents are made available publicly. If you are the author of this thesis or dissertation, and would like to request an exceptional extension of the embargo period, please write to thesisadmin@aucegypt.edu

Call Number

Thesis 2005/97

Location

mgfth;mrs2

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