Preparation, characterization and performance of Pd/SiO2 catalyst for benzene catalytic hydrogenation

Palladium nanoparticles supported on silica were prepared by hydrazine reduction in aqueous medium at room temperature. They were characterized by XRD, TEM, EDX, H-2-adsorption, and H-2-TPD. The catalytic properties were evaluated in the gas-phase hydrogenation of benzene in the temperature range of 75-250 degrees C. Metal particles with a size range of 4.0-25.8 nm were obtained. The metal surface area and hydrogen storage increase with decreasing metal particle size. The H-2-TPD profiles exhibited a main peak appeared at 540 degrees C with two shoulders at lower (445 degrees C) and higher (605 degrees C) temperatures. These peaks were ascribed to strongly adsorbed hydrogen on the surface catalyst. The catalytic activity of the catalysts strongly depends on the metal loading. It increases with decreasing Pd loading. This is ascribed to metal surface area, which increases with decreasing Pd content. (C) 2011 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.