An advanced reaction model determination methodology in solid-state kinetics based on Arrhenius parameters variation

The Arrhenius parameters variation with the conversion degree of reaction is generally due to the overlapping of parallel or consecutive reactions, and the solution of the problem must imply the deconvolution of the overlapping reaction rather than fitting the experimental curve by assuming variable kinetic parameters. The reaction model determination methods are based on the choice of constant Arrhenius parameters and the use of approximations. To solve this major limitation, a new method for the determination of reaction model based on the Arrhenius parameters variation was proposed. This method appears to accurately simulate single-step as well as multi-step reactions kinetics. The proposed method is based on the general rate equation. The method was validated on artificial data calculated for the various dependences of kinetic parameters on conversion. Then, the method was applied for the non-isothermal crystallization kinetics of the amorphous dehydrated Cu4SO4(OH)(6), i.e., Cu4SO4O3 to CuO and CuO center dot CuSO4 in the nano-scale range. The results were compared with the well-known reaction model determination methods and interpreted.