CeO2-ZrO2-WO3-based catalysts for Selective Catalytic Reduction of Nitrogen Oxides by Ammonia

Abstract

Cerium, zirconium and tungsten based catalysts with addition of 3% copper were prepared through the hydrothermal method and incipient wetness impregnation method. The three catalysts produced were named CZW (hydrothermal method), CZW-Cu (hydrothermal method) and CZW-CuImpr (3% Cu impregnated on CZW-support). The pore structure, thermal stability, surface properties and compositions of the catalysts were characterized by XRD, XRF, BET, TGA, TPR, SEM and EDS. Activity test of the catalysts were performed in quartz capillary glass reactor connected to a mass spectrometer. The NO conversion for the catalysts were tested in the temperature range of 150-250C and correlated with a NO calibration of the mass spectrometer. The catalyst synthesized through the hydrothermal method with the addition of 3% Cu was found to exhibit the highest NO conversion of 79.3% at 200C, but also indicated stability over the entire temperature range. The higher catalytic activity was attributed to the addition of small amount of Cu, which enhanced the SCR reaction. The hydrothermal synthesis method was concluded to be the better synthesis method for catalytic activity.