Investigations of nitric bride (NO) and carbon monoxide (CO) adsorption were carried out on the silver-exchanged high silica pentasil zeolite and chabazite-type silico-aluminophosphate materials. Novel Ag-SAPO-34 and Ag-ZSM-5 catalysts were prepared and characterised using routine instrumental techniques. Detailed FTIR studies were carried out on the interaction of NO/CO over Ag-SAPO-34 and Ag-ZSM-5. FTIR spectra indicated the formation of various NO/CO complexes on the silver-exchanged materials. Influence of the NO/CO pressure and evacuation on the surface species have been studied.