Ozone decomposition on Ag/SiO2 and Ag/clinoptilolite catalysts at ambient temperature

Abstract

Silver modified zeolite (Bulgarian natural clinoptilolite) and Ag/silica catalysts were synthesized by ion exchange and incipient wet impregnation method respectively and characterized by different techniques. DC arc–AES was used for Ag detection. XRD spectra show that Ag is loaded over the surface of the SiO2 sample and that after the ion-exchange process the HEU type structure of clinoptilolite is retained. UV–VIS (specific reflection at 310nm) and IR (band at 695cm−1) spectroscopy analysis proved that silver is loaded as a T-atom into zeolite channels as Ag+, instead of Na+, Ca2+, or K+ ions, existing in the natural clinoptilolite form. The samples Ag/SiO2 and Ag-clinoptilolite were tested as catalysts for decomposition of gas phase ozone. Very high catalytic activity (up to 99%) was observed and at the same time the catalysts remained active over time at room temperature.