Ozone influence on oxidation of carbon monoxide in the presence of zeolitecatalysts

The activity of pentasil-type zeolites modified by nickel in the oxidation of carbon monoxide was studied in the presence of ozone and oxygen in the r eaction medium and after treating the surface of the catalysts by these oxi dizing agents. Admixtures of oxygen and ozone increased the activity of the catalysts in this reaction, whereas pretreatment with ozone activated NiO/ H-ZSM-5 and deactivated H-ZSM-5. The IR spectra showed that the sites of ad sorption of CO on the surface of the studied catalysts were substantially d ifferent. It is likely that the sites of CO adsorption on H-ZSM-5 are surfa ce oxygen ions, whereas on the modified catalyst, CO is adsorbed on nickel- oxygen associates.