A reflection-absorption infrared study of carbon monoxide and nitric oxide adsorption on platinum (100)

The adsorption of NO, CO, and NO/CO mixtures, onto Pt(100), is studied by RAIRS. CO and NO are found to adsorb into islands at 300 K, but the islands breakup upon heating to 400 K. Dosing with a mixture of NO and CO at temperatures below 325 K is found to produce a mixed NO/CO island. There is a shift in the CO peak and NO peak during mixed island formation which is attributed to a strong chemical interaction between the adsorbed NO and CO. This interaction is found to produce an increase in the desorption temperature of CO. Autocatalytic behavior is found to arise because of an enhanced reactivity when CO enters a mobile state. The autocatalytic behavior could be responsible for the “surface explosion” reported by Lesly and Schmidt.