Selective catalytic oxidation of n-butylamine over Cu-zeolite catalysts

A series of Cu-modified zeolites (ZSM-5, MOR, MCM-22, Hβ, and SAPO-34) were prepared by the impregnation method and evaluated for n-butylamine selective catalytic oxidation. The structures, surface acidity distributions, redox properties, and Cu species of the catalysts were characterized using a variety of analytical techniques. The results indicate that the type of zeolite used has a significant impact on the existing forms and dispersion of Cu species, affecting the redox properties of the catalysts. Among all considered catalysts, Cu-ZSM-5 exhibited the best catalytic performance. The oxidation activity and N2 selectivity of Cu-ZSM-5 are closely related to the high dispersion of Cu and isolated Cu2+ species and its weaker acidity is a benefit to the adsorption and oxidation of n-butylamine.