Controlled Synthesis And Hydrogenation Properties Of Mesoporous Fe/SiO₂ Hollow Mcrospheres Catalysts

Until now, silicate hollow spheres with large surface areas have received much attention because of their potential applications, such as photonic materials, catalysis, gas sensors, water treatment agents, enzymes and DNA, microchip reactors.The major contributions of this paper mainly includes the following aspects:1. Mesoporous iron-silica composite hollow microspheres with controllable shell thickness have been synthesized by reducing the Fe24Si4O43(OH)2 hollow microspheres at 650℃ and H2 current, which were synthesized via hydrothermal method using SiO2 microspheres as templates, and FeC2O4·2H2O as iron sources. The mesoporous iron-silica composite hollow microspheres were characterized through X-ray diffraction, transmission electron microscopy, and field emission scanning electron microscopy. This material with large BET surface area (145 m2/g) exhibits good catalytic activity and high selectivity in nitrobenzene hydrogenation reaction, showing the potential application as a catalyst in industry.2. The catalytic activity of Fe/SiO2 catalysts were also evaluated by the nitrobenzene hydrogenation reaction at 100℃ and 3.0 MPa. These mesoporous catalysts with large BET surface area exhibit good catalytic activity in nitrobenzene and high selectivity of phenylamine in the end. By studying the influence of the reaction pressure, reaction temperature, reaction time and the structure of the catalyst to the nitrobenzene liquid hydrogenation process, determined the appropriate reaction conditions of the nitrobenzene liquid hydrogenation process. Under this condition, the selectivity rate of the phenylamine was reached to 82% and the conversion rate of the nitrobenzene was reached to 80%.