Selective Catalytic Reduction of NO by NH3 Over Fresh and Sulfated CuO/gamma-Al2O3 Catalysts

CuO/gamma-Al₂O₃ granular catalysts were synthesized by the sol-gel method. Performance of the CuO/gamma-Al₂O₃ catalysts for the selective catalytic reduction (SCR) was explored in a fixed bed adsorption system. The optimum temperature ranges for SCR of NO over the fresh CuO/gamma-Al₂O₃ catalyst are 250~450degC. The maximum activity maintains near to 99% at 350degC. The operating temperature range is increased on the sulfated catalysts. The oxidation property becomes weak when the catalysts are sulfated. The transient behaviors of NH₃ and NO were also studied; it was found that the SCR reaction was zero order with respect to NH₃ and first order with respect to NO. The sulfation on the catalysts improves the adsorption capacity of NH₃ and reduces the adsorption capacity of NO. The adsorbed of NO has little influence on denitrification activity in the actual SCR process.