Low-temperature ozone decomposition, CO and iso-propanol combustion on silver supported MCM-41 and silica

Abstract

Silver modified (5 and 2 wt% loading) mesoporous molecular sieves (H-MCM-41, with Si/Al ratio 20, 40 and 50) and silica were synthesized by incipient wetness impregnation and ion-exchange methods. The obtained catalysts were characterized by different techniques (ICP, XRD, XRF, SEM, FTIR and nitrogen physisorption) and they were tested in heterogeneous catalytic decomposition of ozone and oxidation reactions involving ozone at ambient temperature. All the mesoporous catalysts have very high catalytic activities towards ozone decomposition at room temperature and they do not reveal any deactivation with the time on stream. The activities of the catalysts are enhanced upon increasing the amount of supported silver, decreasing the support acidity and modifying the catalyst with some additional metal having basic properties, such as Ce. The most active catalyst in the reaction of ozone decomposition—5Ag-H-MCM-41-50, shows also high activity at ambient temperature in the oxidation of CO and iso-propanol with ozone.