Effect of calcination temperatures on ammonia selective catalytic oxidation by Cu/SSZ-13 catalysts

Abstract

The Cu/SSZ-13 catalysts prepared by the impregnation method were applied to ammonia selective catalytic oxidation (NH3-SCO). The effect of the calcination temperature on the catalytic performance was inverstigated. The structural and physico-chemical properties of the catalysts were investigated by XRD, N2 adsorption-desorption isotherms, XPS, NH3-TPD and H2-TPR. It is found that the increase of calcination temperature favors the ammonia conversion at low temperatures. Meanwhile, overhigh calcination temperature (>500 °C) would lead to the decrease of catalytic activity. The Cu/SSZ-13-500 catalyst shows the highest catalytic performance and exhibits more than 70% NH3 conversion at 200 °C. The NH3-TPD and H2-TPR results confirmed that Cu/SSZ-13-500 owned more Lewis acid sites and CuO species, which were beneficial for ammonia adsorption and activation.