Mechanistic study of aniline methylation over acidic and basic zeolites Y

I.I. Ivanova, E.B. Pomakhina, A.I. Rebrov, Yu.G. Kolyagin, M. Hunger and J. Weitkamp

Stud. Surf. Sci. Catal. (in press)

ABSTRACT. 13C MAS NMR has been performed in situ under batch conditions to investigate the mechanism of aniline alkylation with methanol on acidic zeolite H-Y and basic zeolite CsNa-Y impregnated with cesium hydroxide. The results suggest that on acidic zeolite H-Y, methanol reacts with zeolitic hydroxyl groups to give surface methoxy groups which, in turn, play a role as alkylating species in aniline methylation. On the basic zeolite Y, methanol is converted into formaldehyde, which is responsible for the N-alkylation. Both on acidic and basic zeolites, N-methylaniline is the primary alkylation product. Toluidines and N-methyltoluidines are formed only on the acidic zeolite at elevated temperatures after complete conversion of methanol into N-methylaniline.

Laboratory of Kinetics and Catalysis