Influence of calcination temperature on selective catalytic reduction of NOx with NH3 over CeO2-ZrO2-WO3 catalyst

A series of CeO2-ZrO2-WO3 catalysts for the selective catalytic reduction (SCR) of NO with NH3 were prepared by hydrothermal method. The influence of calcination temperature on the catalytic activity, microstructure, surface acidity and redox behavior of CeO2-ZrO2-WO3 catalyst was investigated using various characterization methods. It was found that the CeO2-ZrO2-WO3 catalyst calcined at 600 °C showed the best catalytic performance and excellent N2 selectivity, and yielded more than 90% NO conversion in a wide temperature range of 250–500 °C with a space velocity (GHSV) of 60000 h−1. As the calcination temperature was increased from 400 to 600 °C, the NO conversion obviously increased, but decreased at higher calcination temperature. The results implied that the higher surface area, the strongest synergistic interaction, the superior redox property and the highly dispersed or amorphous WO3 species contributed to the excellent SCR activity of the CeO2-ZrO2-WO3 catalyst calcined at 600 °C.

NH3-SCR catalytic performance over CZW catalysts calcined at different temperatures (Reaction conditions: 600 ppm NO, 600 ppm NH3, 5% O2, balance N2, GHSV= 60000 h−1) (a) NO conversion over the CZW catalysts; (b) N2O concentration over the different catalysts; (c) The influence of reaction time on catalyst stabilityFigure optionsDownload as PowerPoint slide