The analysis of temperature programmed desorption experiments of systems with lateral interactions; implications of the compensation effect

In this paper we have investigated problems that arise when analyzing TPD spectra of desorption processes in which lateral interactions between adsorbed species are present. Dynamic Monte Carlo (DMC) simulations are used to simulate the effect of adsorbate interactions on TPD spectra and we applied the most common methods to derive the activation energy and the pre-exponential factor. The extraction of the kinetic parameters in the zero-coverage limit works well for all methods. The extraction of the coverage dependent values on the other hand is quite difficult since a ‘forced’ compensation effect can occur, leading to false values for the pre-exponential factor as well as false values for the activation energy. Finally, we suggest a new approach that can be used to estimate the activation energy over the entire coverage range.