Thermogravimetric (TG) measurements were carried out to study the chlorination of γ-alumina by gaseous CCl4 in the temperature range 650-1123 K at 102-104 Pa CCl4 partial pressure. Experimental results indicate that the reaction involves two main steps: the substitution of oxygen atoms on the surface by chlorine leading to a mass gain and the volatilization of the main gaseous product, aluminium chloride, with a mass loss of the sample. These processes take place simultaneously during the course of the reaction. A kinetic model is proposed to describe these two steps providing a simple method for linearization of the initial part of the isothermal TG curves. Temperature and partial pressure dependence of the reaction rate and of the steady-state surface coverage are discussed on the basis of the proposed kinetic model. Activation energies and reaction orders are calculated for these two steps.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry