The reaction of Cl2with γ-alumina has been studied in the temperature range 300-1100 K by thermogravimetric (TG) and calorimetric (DSC) methods. Also. GC and MS techniques were used for the analysis of the gas phase, and a volumetric method for studying the adsorption of Cl2 on Al2O3. Measurable adsorption was found only below 500 K. Above 420 K, however, an exchange of surface oxygens by chlorine also takes place, resulting in a mass gain and an exothermic heat effect. The extent of this exchange reaction vigorously increases with temperature, suggesting that oxygens able to take part in the O(surf) + Cl2 = 2Cl(surf) + 1 2O2 reaction are energetically heterogeneous. Above 870 K the fast exothermic exchange reaction is accompanied by a slower, endothermic processs, considered as surface rearrangement together with the formation and volatilization of AlCl3.
ASJC Scopus subject areas
- Condensed Matter Physics
- Physical and Theoretical Chemistry