关键词: 钯, 铂, 活性炭, 加氢脱硫

Abstract:  The Pd and Pt hydrodesulfurization (HDS) catalysts supported on coconut shell activated carbon, nut shell activated carbon, and wood activated carbon were prepared by an incipient wetness impregnation method. The HDS catalytic performances of these noble metal catalysts supported on different activated carbons were investigated by using a model feed containing 0.8 % dibenzothiophene (DBT) in decalin. The results indicated that the dispersion of Pd and Pt could be enhanced by increasing the amounts of either the acidic oxygen-containing groups or the basic groups on the surface of the support. In the HDS of DBT over the Pd/C and Pt/C catalysts, the selectivity toward the direct desulfurization pathway (DDS) was higher than that toward the hydrogenation pathway (HYD). Both the HDS activity and the DDS pathway selectivity of the supported Pt catalysts were significantly higher than those of the supported Pd catalysts. The HDS catalytic performances of the Pt/C and Pd/C catalysts were mainly determined by the surface groups of the support and their distributions. An increase of the surface acidic oxygen-containing groups led to an increase of the HYD selectivity and the stability of the Pd and Pt catalysts, but a decrease in their C-S bond cleavage activity. On the other hand, the basic groups showed a positive effect on the C-S bond cleavage activity of Pd/C and Pt/C and a negative influence on their stability.