SELECTIVE CATALYSTIC REDUCTION OF NO BY NH3 OVER SOL-GEL-DERIVED CUO/Γ-AL2O3 CATALYST

摘要

CuO/γ-Al2O3 granular sorbents with nanostructed mesoporous structure were synthesized by the modified sol-gel method. Performance of the CuO/γ-Al2O3 sorbents 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/γ-Al2O3catalyst samples are 250～400°C. The maximum efficiency maintains near to 98% at 350°C. Preliminary tests were carried out to study the behavior of NO and NH3 over fresh sorbents in the presence of oxygen. The NO oxidation experiments revealed that NO was oxidized to NO2 over the CuO/γ-Al2O3 sorbents. The NH3 oxidation experiments revealed that both NO and N2O were produced gradually with temperature raising. The NH3 and NO desorption experiments showed that NH3 and NO could be adsorbed on CuO/γ-Al2O3 granular catalysts and the NO2 intermediate species could play an important role in the reaction mechanism.