Mechanistic study of aniline methylation over acidic and basic zeolites Y

I.I. Ivanova (a), E.B. Pomakhina (a), A.I. Rebrov (b), Yu.G. Kolyagin (a), M. Hunger (c) and J. Weitkamp (c)

Stud. Surf. Sci. Catal. 135, 2001, 23-P-12 (electronic version, 8 pages).

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