Denitration performance of CuO/γ-Al2O3 catalysts modified by CeO2

Abstract

Abstract CuO-CeO2/γ-Al2O3 catalysts with different CeO2 loadings were synthesized by wet impregnation method. Selective catalytic reduction (SCR) of NO over the two kinds of catalysts was carried out in a fixed bed reactor. CuO-CeO2/γ-Al2O3 catalysts reached NO conversion efficiency 65% at 150 °C and maintained over 80% at 200-400 °C, The maximum efficiency is stably reached at 300 °C. CuO-CeO2/γ-Al2O3 catalysts showed wider temperature range than that of the CuO/γ-Al2O3. NH3-TPD tests were carried out to study the adsorption and oxidation behavior of NH3 over CuO-CeO2/γ-Al2O3 catalysts with different CeO2 loadings in the presence of oxygen. The NH3 adsorption and activation performance were modified attributing to the modification of the Surface acidity of the CuO-CeO2/γ-Al2O3 catalysts. The mass transfer was improved due to the promotion of the pore numbers in 8-50, 50-200μm which was another NO conversion promotion factor. Surface acidity and the pore volume decreased obviously as CeO2 overloaded in CuO-CeO2/γ-Al2O3, with a negative influence of NH3 adsorption and oxidation performance. It is considered to be the main factor of the NO conversion efficiency decreased.