Criteria for determining the mechanisms of solid state reactions from non-isothermal data

Abstract

A comprehensive procedure for analyzing sets of dynamic data collected at various rates of heating, and two powerful criteria for ascertaining the mechanism are given. (1) The kinetic parameters are first derived by linearizing {In [g(ɑ)] - In[p*(x).T²]} versus l/T. (2) The correct activation energy (E*) is then computed, without invoking the mechanism, by linearizing {In(q) -In[p*(x).T²]} versus l/T; by comparing the correct E* with the values computed in the first step, the correct mechanism may be identified. (3) Finally, using the correct E*, the pre-exponential factors (A) are computed for different mechanistic functions, from the intercept of the above fit; by comparing the A-values computed in the first and third steps, the mechanism can be established unequivocally.