Relationship Between Metal Dispersion, Hydrogen Desorption, and Activity for Benzene Hydrogenation Over Pd/SiO₂ Catalysts

Abstract

A series of Pd/SiO₂ catalysts with Pd loadings from 1–10 wt% were prepared by aqueous hydrazine reduction. They were characterized by XRD, TEM, EDX, H₂ chemisorption, and H₂-TPD. The catalytic performances were evaluated in benzene hydrogenation in the temperature range 100–250°C. The metal dispersion (mean particle size 6.8–28.4 nm) and hydrogen reservoir increase with decreasing metal content. The catalytic activity of the Pd/SiO₂ catalysts was found influenced by the reaction temperature and metal dispersion. The activity increases with metal dispersion. This might be ascribed to the Pd sites, which increase with the increase of the metal dispersion.

Keywords:

• hydrazine
• hydrogenation
• metal dispersion
• palladium