Two types of uncertainty in the values of activation energy

The activation energies of the same process are often reported to have different values, which are usually explained by the differences in experimental conditions and sample characteristics. In addition to this type of uncertainty, which is associated with the process (DeltaE(process)) there is an uncertainty related to the method of computation of the activation energy (DeltaE(method)). For a method that uses fitting single heating rate data to various reaction models, the value of DeltaE(method) is large enough to explain significant differences in the reported values of the activation energy. This uncertainty is significantly reduced by using multiple heating rate isoconversional methods, which may be recommended for obtaining reference values for the activation energy.