Three-phase nitrobenzene hydrogenation over supported glass fiber catalysts: reaction kinetics study

The catalytic properties of Pd and Pt supported on woven glass fibers (GF) were investigated in the three-phase hydrogenation of nitrobenzene (NB). Over all catalysts, a 100% yield of aniline was attained. The catalytic activity for the best catalysts was two times higher than the activity of com. Pt/C catalyst traditionally used for liq.-phase hydrogenation. The intrinsic reaction kinetics were studied and a reaction scheme is suggested. The direct formation of aniline from NB was obsd. over Pd/GF with traces of intermediates. Four intermediate products were detected during aniline formation over Pt/GF: nitrosobenzene, phenylhydroxylamine, azoxybenzene, and azobenzene. The Eley-Rideal kinetic model fits the exptl. data well. The parameters of the model were detd. as a function of initial NB concn. and hydrogen pressure. Pt and Pd supported on GF in woven fabrics are suggested as suitable materials for reactors with a structured catalytic bed in multiphase reactor performance. [on SciFinder (R)]