College of Electrical and Power Engineering,Taiyuan University of Technology

The most economical denitration method is the direct decomposition of NO into the most environmentalfriendly and cleanest N2 and O2 in the action of the Cu-ZSM-5 catalyst. There are a lot of alkali metals in thehigh temperature flue gas. However, the alkali metals can reduce the catalytic activity, shorten the service lifeof the catalyst, and cause an irreversible deactivation of the catalyst. The MZ5 (M: Cu, Ce, Zr, CuCe, CuZr,CuCeZr) catalysts were prepared by the ion exchange method, and the K ions were loaded onto the MZ5 catalystsby the incipient wetness impregnation method. The results of the denitration experiments indicated that at the optimalreaction temperature of 550 ℃, the NO conversion rate of the CuCeZrZ5 catalyst increased from 53% to 58% com⁃pared with that of CuZ5; the NO conversion rate of the KCuCeZrZ5 catalyst increased from 39% to 52% comparedwith that of KCuZ5; and the NO conversion rate of the KCuCeZrZ5 catalyst increased from 53% to 52% comparedwith that of CuZ5. The ICP, SEM, XRD, BET, XPS, H2 -TPR and O2⁃TPD were used to analyze thoroughly the ele⁃ment content, micro morphology, skeleton structure, pore law, copper species, chemical adsorption oxygen, copperion reduction temperature and oxygen desorption temperature in active species. The characterization resultsshowed that the introduction of Ce and Zr did not damage the framework structure, crystallinity and grain sizeof the catalyst, on the other hand, it promoted the formation of more oxygen vacancies and the active component{Cu—O—Cu}2+in the catalyst, and enhanced the oxygen storage and transport capacity of the catalyst. When K+ wasintroduced, the denitrification activity of CuZ5 catalyst decreased obviously, the pore structure deteriorated, and CuOwas formed by the migration of K+with the active component {Cu—O—Cu}2+. K+ preferentially combined with Ce spe⁃cies, which effectively protects the unique three⁃dimensional cross⁃pore structure of ZSM-5, reduces the migration ofCu2+ to form CuO and promotes the redox cycle between the active component {Cu—O—Cu}2+ and {Cu—□—Cu}2+.