Atmospheric Discharge Plasma Enhanced Preparation of Pd/TiO2 Catalysts for Acetylene Selective Hydrogenation

摘要

A series of Pd/TiO2 catalysts were prepared by incipient wetness impregnation method followed by atmospheric discharge plasma treatment. In order to study the influences of plasma treatment on the catalysts, the samples were characterized by XRD, TPR, TPD, XPS and TEM technologies. It was found that the plasma treatment catalysts possessed a higher acetylene conversion and ethylene selectivity compared to those of the untreated sample. The enhanced performance of the plasma treated catalyst was mainly dependent on two main effects. On one hand, the treated catalyst possessed a higher metal Pd dispersion, which resulted in the easier activation of acetylene. On the other hand, the surface electron density of metal Pd on the treated catalyst got enhanced compared to that of untreated sample, because of the stronger interaction between TiO2 support and metallic Pd, helping the more desorption of ethylene species from the surface of catalyst.