Study on the preparation and catalytic performance of bimetallic Ce-Mn/ZSM-5 catalyst for selective catalytic reduction of nitric oxide by NH₃

A series of Ce-Mn/ZSM-5 catalyst with different mass ratios of Ce and Mn was prepared by impregnation method, and the influence of Ce loading on denitrification performance was investigated in a fixed-bed reactor. XRD, TEM, NH₃-TPD, H₂-TPR, in-situ DRIFTS were used to characterize the catalysts. The results show that the bimetallic Ce-Mn/ZSM-5 have a broad active temperature window. Especially, the catalyst with Ce/Mn mass ratio of 0.4 has the best denitrification efficiency, and the denitrification rate can be higher than 80% between 266 and 465℃, and up to 97.28% at 370℃.Manganese and cerium species can be well dispersed on the surface of the support without changing the crystal structure of ZSM-5.0.4Ce-Mn/ZSM-5 catalyst has abundant acidic sites, good redox performance. There are both E-R mechanism and L-H mechanism in NH₃-SCR reaction.