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

Abstract A comparative study of the reactivity between copper(I) chloride and three types of Cu 3 Si obtained in a molten medium (Cu 3 Si-Ref) and from mechanical activation following an annealing process (Cu 3 Si-M2AP) or a self-propagating high-temperature synthesis (Cu 3 Si-MASHS) was performed by thermogravimetry under vacuum using non-isothermal and isothermal methods of kinetic measurement. It was established that for the three Cu 3 Si/CuCl systems, the acceleration and decay stages in the temperature range 145–215°C are very closely approximated by an equation of the Prout–Tompkins type where an autocatalytic process was proposed. The lower apparent activation energy obtained for the Cu 3 Si-MASHS/CuCl system (63 kJ mol −1 against 68 and 78 kJ mol −1 for Cu 3 Si-M2AP and Cu 3 Si-Ref, respectively) has been attributed to a small grain size which induces nanoscale contacts between reactants and impedes CuCl to sublime.