Vapor-phase synthesis of ε-caprolactam (ε-C) from cyclohexanone oxime (CHO) has been studied at 300-400°C and atmospheric pressure using AlSBA-15(X) catalysts with different Si/Al mol ratios X in a fixed-bed, integral-flow reactor. The catalysts were characterized with ICP-AES, XRD, TEM, N 2 adsorption, 27A1 and 29Si MAS-NMR, FT-IR and TPD of ammonia. A decrease of X value in AlSBA-15(X) diminishes both the BET surface area and the unit cell length but enhances the acid amount. The catalytic activity correlates with the catalyst acidity. AlSBA-15(10) exhibits excellent catalytic performance.
