A new quantitative interpretation of temperature-programmed desorption spectra from heterogeneous solid surfaces, based on statistical rate theory ofinterfacial transport: The effects of simultaneous readsorption

We have recently proposed a new method of estimating the surface energetic heterogeneity of solids from temperature-programmed desorption (TPD) spectr a analyzed in terms of the statistical rate theory of interfacial transport (SRTIT) (Chem. Anal. 1996, 41, 1057; In Equilibria and Dynamics of Gas Ads orption on Heterogeneous Solid Surfaces; Elsevier: New York, 1996.). SRTIT is a new theoretical approach linking the rate of desorption kinetics to th e chemical potential of the adsorbed molecules and the molecules in the gas phase. While applying SRTIT to analyze TPD spectra, one arrives at the con densation approximation (CA) for the adsorption energy distribution. Having obtained the CA function, one can calculate the exact adsorption energy di stribution using well - known methods (Adsorption of Gases on Heterogeneous Surfaces; Academic Press: London, 1992). The analysis of TPD spectra in te rms of SRTIT is improved here by taking into account the readsorption kinet ics. As an example of its application, an analysis of a TPD spectrum of hyd rogen desorption from an alumina-supported catalyst is presented.