Infrared study of the reaction of carbon monoxide and ammonia over supported rhodium catalysts

Abstract

Infrared spectra are reported of ammonia and carbon monoxide coadsorbed on rhodium dispersed on SiO₂, Al₂O₃ and TiO₂ supports. The formation of isocyanate on rhodium was followed by spillover on the the alumina and titania supports but not on to silica. Ammonia promoted the adsorption of CO on Rh/TiO₂ to give bicarbonate ions on the titania support. The NO/CO reaction over Rh/TiO₂ was studied for comparative purposes. The effects of ammonia on infrared bands due to adsorbed CO on rhodium are discussed.