WO3 promoted Mn–Zr mixed oxide catalyst for the selective catalytic reduction of NOx with NH3

Abstract

A series of WO3-doped Mn–Zr mixed oxide catalysts were investigated for the selective catalytic reduction of NOx by NH3 (NH3–SCR). It was found that the added WO3 significantly enhanced the catalytic performance of Mn–Zr mixed oxide catalyst for NH3–SCR of NOx. In situ diffuse reflectance infrared transform spectroscopy (DRIFTS) studies revealed that the highly dispersed WO3 not only resulted in more acid sites formed on the catalyst surface, but also inhibited the adsorption of the inactive nitrate specie, leaving more active sites available for the adsorption of NH3. In addition, the synergetic effect between W and Mn contributes to improving the redox property of the catalyst. Therefore, the high catalytic deNOx performance was obtained over WO3-promoted Mn–Zr mixed oxide catalyst.