An FTIR study of the activation of CO and NO molecules on Cu+ sites in CuZSM-5 – The effect of coadsorbed electron donor molecules

IR spectroscopic studies evidenced that Cu+ ions coordinating basic molecules (ammonia, water, and pyridine) influenced both the CO and NO bond order. The significant downshift of the stretching frequency of the NO and CO bands indicates a considerable weakening of the multiple bonds. The effect was found to be the most important for pyridine as the molecule of the strongest electron donation properties.