Resumen de Liquid-phase hydrogenation of m-dinitrobenzene over platinum catalysts
Hugo Rojas, Gloria Borda, Patricio Reyes, María Helena Brijaldo, Jesús Valencia
The m-dinitrobenzene hydrogenation to m-phenylenediamine in liquid phase was studied with platinum supported on SiO2, TiO2, Al2O3 and Nb2O5 catalysts. Incipient impregnation method was used to prepare the catalysts with 1wt% of Pt. The effect of the support and the reduction temperature (473 K or 773 K) were analyzed. The materials were characterized by X-ray diffraction (XRD), nitrogen physisorption (77 K), hydrogen chemisorption (298 K), transmission electron microscopy (TEM), temperature programmed reduction (H2-TPR) and temperature programmed desorption of ammonia (NH3-TPD). The results showed that Pt/ TiO2 (HT) catalyst had a higher yield (60%) toward m- phenylenediamine and conversion level (98.2%) of m-dinitrobenzene. This behavior can be attributed to the reduction of PtO crystallites to metallic Pt, small particle size and the strong metal-support interaction due to the migration of TiO species on the Pt crystallites.
