Process and catalyst for the preparation of aromatic amines by hydrogenation in the gas phase

摘要

Prodn. of an aromatic amine of formula Ar-NH2 (I) comprises gas phase hydrogenation of a nitroaromatic of formula ArNO2 (II) with H2 over a stationary catalyst (C). The H2 supply to the catalyst is 30-6000 equiv. per NO2 gp. equiv. Ar = phenyl (substd. by R1 and R2); R1 = H, Me or Et; R2 = H, Me, Et, NH2. (C) comprises Pd and Pb on a graphite or graphitised coke support with a BET surface area of 0.2-10 m<2>/g, contg. 0.001-7 wt.% Pd w.r.t. total catalyst and 0.1-50 wt.% Pb w.r.t. Pd. Also claimed is (C), esp. for the hydrogenation of nitro-aromatics.