CO AND NO ADSORPTION ON COPPER-CONTAINING ZEOLITE - A THEORETICAL AB-INITIO STUDY

Ab initio calculations were performed to simulate the interaction betw een CO or NO and copper-containing zeolite at the SCF level. The zeoli te catalysts were modelled by a molecular cluster of composition H8Si3 AlO4Cudelta+ with delta = 0, 1. For delta = 0 the oxidation state of t he Cu atom corresponds to 1+ in Cu+/zeolite, while for delta = 1 it is equal to 2+ in Cu2+/zeolite. It was found that only Cu+/zeolite shoul d be responsible for CO and NO adsorption from the gas phase. The calc ulated heats of adsorption compare well with available experimental da ta and together with adsorption geometries allow us to interpret the o bserved IR data.