CO adsorption on Al-Zr at room temperature

A study of CO adsorption on room temperature Al-Zr has been done using Auger electron spectroscopy and gas pressure measurements. The atomic surface composition of clean Al-Zr surfaces prepared in UHV by Ar+ sputtering, was measured as a function of CO pressure and exposure time. The adsorbed C and O have the same rate constants and surface concentrations for exposures less than 2 Langmuir. Above this exposure quasi-saturation occurs. The measured sticking probability of CO on Al-Zr is constant, S = 0.7 +- .3, for fractional coverage theta less than or equal to 0.5. Above this point S decreased rapidly. The effect of surface roughness on the apparent sticking coefficient has been calculated by a Monte-Carlo simulation. Reactivation of Al-Zr by heat treatment to 7000C has also been studied