High Resistance of Cu-Ferrierite to Coke Formation During NH3-SCR in the Presence of n-Decane

Selective catalytic reduction of NOx by NH3 over Cu-FER and Cu-ZSM-5 in the presence of n-decane and SO2 was investigated. NOx conversion over Cu-ZSM-5 decreased in the presence of n-decane, owing to inhibition of the active sites by coke formation. In contrast, coke formation was negligible over Cu-FER, which maintained its NOx conversion activity even in the presence of decane. Coke formation was negligible over H-ZSM-5 and H-FER supports, which suggests that Cu species were involved in coke formation. Temperature-programmed reduction by H-2 and electron spin resonance spectroscopy indicated that [Cu-O-Cu](2+) was probably the Cu species involved in coke formation over Cu-ZSM-5.