LOW-TEMPERATURE ADSORPTION-KINETICS OF CO ON PT(111) DERIVED FROM NONEQUILIBRIUM TIME-RESOLVED ELECTRON-ENERGY-LOSS SPECTROSCOPY MEASUREMENTS

Using time-resolved high-resolution electron-energy-loss spectroscopy, nonequilibrium adsorption of CO on Pt(111) has been measured and quantitative comparison made with equilibrium absorption over the whole range of coverage between 300 and 100 K. It is unambiguously shown that there is no site conversion of CO between on-top and bridge sites below 150 K. The ambiguity of equilibrium parameters derived from equilibrium data without knowledge of nonequilibrium data is demonstrated. An adsorbate-induced surface-reconstruction model has been proposed to explain the adsorption kinetics of CO on Pt(111) between 100 and 400 K.