COVERAGE DEPENDENT DESORPTION MEASUREMENTS OF CO/CU(001)

We report time-resolved electron energy loss spectroscopy measurements of the coverage-dependent kinetic parameters for the thermal desorption of CO from Cu(001). Large, parallel increases in the activation energy for desorption and desorption prefactor are observed as a function of coverage. The activation energy away from zero coverage differs significantly from the measured isosteric heat of adsorption. The significance of these results is discussed in terms of applicable statistical models. We deduce the existence of an unusual temperature dependence in the adsorbate configurational entropy. © 1990.