以全硅MCM—41为载体制备W系深度加氢脱硫催化剂

用全硅MCM－41担载Ni-W和Co-W制备了深度加氢脱硫催化剂，并在中压固定床反应器上分别考察了对二苯并噻吩（DBT）和高硫直接馏柴油的加氢脱硫性能。结果表明，全硅MCM－41担载制成的W系催化剂表现出很高的加氢脱硫活性，其中Ni-W/MCM-41活性高于Co-W/MCM-41，但两类催化剂的最佳Ni(Co)/W原子比均为0．75。从加氢脱硫产物分布看，两类催化剂的脱硫反应路径不同，在Co-W/MCM-41上主要通过氢解脱硫，而在Ni-W/MCM-41上则是通过氢解以及先经芳环加氢后脱硫的两条路径来进行，对Ni-MCM-41来说，加氢活性随温度升高而升高。

PREPARATION OF W-BASED CATALYSTS SUPPORTED BY SILICEOUS MCM-41 FOR DEEP HYDRODESULFURIZATION

W based deep hydrodesulfurization (HDS) catalysts were prepared by impregnating Ni W and Co W species on siliceous MCM 41. The HDS activity of prepared catalysts was evaluated in a fixed bed reactor by using a model fuel containing 0.5% dibenzothiophen (DBT) in decalin and a straight run diesel containing 2.83% S as the feedstocks. Results indicated that the optimal atomic ratio of n (Ni or Co)/ n (W) for both Ni W/MCM 41 and Co W/MCM 41 are 0.75, while Ni W/MCM 41 exhibited much higher HDS activity than Co W/MCM 41. The product distribution suggested that the two catalysts took different reaction routes for hydrodesulfurization. For Co W/MCM 41catalyst, hydrodesulfurization took place mainly through hydrogenolysis, i.e. DBT to form BP(biphenyl). As for Ni W/MCM 41 catalyst, both hydrogenolysis and hydrogenation took place, i.e. DBT firstly hydrogenated to form tetrahydro DBT(TH DBT), then desulfurized to form cyclohexyl benzene(CHB). Ni W/MCM 41 catalysts showed excellent performance in the hydrodesulfurization of both DBT and a high sulfur containing stright run diesel, suggesting that siliceous MCM 41 is a promising support for deep HDS catalysts.