Infrared Spectra of Carbon Monoxide and Carbon Dioxide Adsorbed on Chromia–alumina and on Alumina

Infrared spectra of CO and CO 2 adsorbed on chromia–alumina and on alumina surfaces have been determined. A band near 2200 cm− 1 formed by CO on both surfaces at room temperature was due to a weak, non-activated sorption, but also contained a contribution from a more strongly sorbed, activated species on the chromia–alumina. The assignment of this band was discussed in some detail. Bands in the region 1200–1800 cm− 1 were considered in terms of surface CO 2 − species, although in certain instances the appearance of bands at 1750 and 1430 cm− 1 may have indicated carbonate ion formation.