Reactions of CO and NO on Mg promoted cobalt

Nitric oxide adsorption and coadsorption with carbon monoxide have been studied using XPS and TDS on clean and magnesium covered polycrystalline cobalt. At small NO exposures, the adsorption on clean cobalt at room temperature was dissociative but at exposures over 3 L molecular adsorption was also observed. Submonolayer coverage of Mg had a negligible effect on the adsorption of NO, but a full monolayer coverage decreased both the molecular and the dissociative adsorption of NO. In the NOCO coadsorption the NO molecules block the adsorption of CO and induce removal of the preadsorbed CO molecules on the clean and Mg covered cobalt. The presence of Mg stabilizes the CO molecules against the attack by NO molecules.