Influence of preparation method on the performance of Pd/ ZrO₂-Al₂O₃ catalysts for HDS

Abstract

ZrO₂-Al₂O₃(I) and ZrO₂-Al₂O₃(S) mixed supports were prepared using impregnation and sol-gel methods, separately. Influences of preparation methods on the properties of Pd based catalysts for hydrodesulphurization (HDS) of thiophene were studied. The prepared samples were characterized by means of XRD, H₂-TPD, H₂-TPR, XPS, NH₃-TPD, H₂ chemisorption and BET surface area. Pd/ZrO₂-Al₂O₃(S) catalyst supported on ZrO₂-Al₂O₃(S) exhibited much higher HDS activity than that of the Pd/ZrO₂-Al₂O₃(I) catalyst supported on ZrO₂-Al₂O₃(I). As compared with Pd/ZrO₂-Al₂O₃(I) catalyst, Pd/ZrO₂-Al₂O₃(S) catalyst has higher dispersion, more acid sites and stronger interaction between palladium and mixed support, which presented an increasing driving-force toward the catalyzed conversion of thiophene.