Abstract: Quantum chemistry method has been employed to investigate the microscope mechanism of the adsorption of carbon monoxide (CO)on alkali-ion (Li+,Na+,K+,Rb+,Cs+) exchanged Y zeolites.In addition,the change of IR spectrum after CO adsorbed on zeolites has been studied in detail.Results showed that multi-molecule adsorption could take place between CO molecules and alkali-ion exchanged Y zeolites and the adsorbed behavior was similar with the structure.After single molecule or two molecules absorption,the IR spectrums of CO both showed blue shift.Two new IR adsorption bands appeared when two CO molecules were adsorbed on zeolites,and the vibration frequency was lower than that for single molecule absorption.When CO adsorbed on Li-Y or Na-Y,the vibration frequency for single molecule adsorption and two molecules adsorption changed greatly.However,the vibration frequency changed slightly when single molecule and two molecules adsorbed on K-Y,Rb-Y or Cs-Y zeolites,and the vibration frequency values for the two CO molecules were closed when dimer molecules adsorption occurred.Energy results showed that the interaction between CO and alkali ion exchanged Y zeolites tended to be weak with the increase of alkali ion radius. 

Key words: quantum chemistry, zeolites, alkali metal, CO adsorption, IR