Simulating temperature programmed desorption directly from density functional calculations: How adsorbate configurations relate to desorption features

Abstract

DFT calculations are used to explain states in TPD spectra by relating the differential adsorption energies for different configurations to the desorption features. A plot of the number of molecules versus these temperatures strongly resembles the TPD spectrum. The calculations were also used to obtain pairwise additive potentials. These potentials were used in a dynamic Monte Carlo model to simulate the TPD spectrum. The spectra obtained from both approaches are in good agreement, validating the approximation that lateral interactions can be added on a pairwise basis.