The significance of compensation effects appearing in data published in computational aspects of kinetic analysis: ICTAC project, 2000

Examination of the results reported for the recent International Congress on Thermal Analysis and Calorimetry (ICTAC) kinetics project [Thermochim. Acta 355 (2000) 125] shows that, from kinetic analyses of identical sets of numerical data measurements, different workers, using different computational procedures, obtained significantly different kinetic parameters. The reported Arrhenius parameters, A (frequency or pre-exponential factor) and E (activation energy), calculated from the data sets supplied, showed apparent (approximate) compensation trends. Thus, when reviewing or applying the values of Arrhenius parameters reported for innumerable and diverse rate processes in the literature, the uncertainties in the magnitudes of A and E (often not even estimated or discussed) cannot be regarded as arising only from differences in the sample or experimental conditions, but must also include consideration of the mathematical and computational methods used. Variations of either type can lead to compensation effects and the recognition of compensation can be a valuable indication of a need to explore the source of this behavior. An observed kinetic compensation effect (KCE) can, thus, be a result of differences in the sample or experimental conditions, be an indication of complex reaction controls, or, as shown in this survey, may be a computational artifact. (C) 2002 Elsevier Science B.V. All rights reserved.