Reactivity of Cu3Si of different genesis towards copper(I) chloride

A comparative study of the reactivity between copper(I) chloride and three types of Cu3Si obtained in a molten medium (Cu3Si-Ref) and from mechanical activation following an annealing process (Cu3Si-M2AP) or a self-propagatin g high-temperature synthesis (Cu3Si-MASHS) was performed by thermogravimetr y under vacuum using non;isothermal and isothermal methods of kinetic measu rement. It was established that for the three Cu3Si/CuCl systems, the accel eration and decay stages in the temperature range 145-215 degrees C are ver y closely approximated by an equation of the Prout-Tompkins type where an a utocatalytic process was proposed. The lower apparent activation energy obt ained for the Cu3Si-MASHS/CuCl system (63 kJ mol(-1) against 68 and 78 kJ m ol(-1) for Cu3Si-M2AP and Cu3Si-Ref, respectively) has been attributed to a small grain size which induces nanoscale contacts between reactants and im pedes CuCl to sublime. (C) 2000 Elsevier Science B.V. All rights reserved.