Catalytic Decomposition of Ozone Gas by a Pd Impregnated MnO2 Catalyst

Abstract

A new catalyst, which was made of MnO2 impregnated with Pd for decomposition of high humidity ozone gas, was developed and its catalytic activity decrease was analyzed in a finite difference type fixed bed reactor. The activity of the catalyst was higher than that of other catalysts and an activated carbon and does not decrease so much for a long term. Therefore, its lifetime is very long. The reaction rate was shown as a first-order reaction equation for each catalyst in any operation time both under dry and wet conditions. The rate-determining step was considered to be a chemical reaction of ozone. The reaction rate constant kt decreased through two steps, fast in an early period and slowly afterward. Then, kt was analyzed as the function of operation time t and inlet concentration C0 at each humidity. From the analysis, the ozone removal performance in any size of reactor and in any time became possible to predict.