Angular distributions of sulphur Auger emission from H2S and S adsorbed on NI(100) surfaces

We have studied at 300 K and under low pressures the adsorption and reactivity of gaseous carbon monoxide on platinum with preadsorbed oxygen. The reaction is first order dependent and evidently proceeds through strongly adsorbed oxygen and weakly bond carbon monoxide species interactions. Three tentative interpretations are given in order to explain the independence of the reaction rate on the oxygen coverage in a large domain. One of them, purely geometrical, is of course inadequate at low coverages: the two others attribute the main reactivity to the α or β states, observed when using temperature programmed desorption.