W 对 W-Ni2P/SBA-15催化剂结构及二苯并噻吩氢脱硫性能的影响

 以硝酸镍为镍源，磷酸氢二铵为磷源，介孔分子筛 SBA-15为载体，采用共浸渍法制备Ni₂P/SBA-15前驱体，再将一定量的偏钨酸铵水溶液引入，采用程序升温还原制备了一系列 W-Ni₂P/SBA-15催化剂。采用 XRD、N₂吸附-脱附、NH₃-TPD 和 XPS 表征了催化剂的结构，并评价了催化剂的二苯并噻吩加氢脱硫活性。结果表明，W-Ni₂P/SBA-15催化剂中均只存在Ni₂P物相；催化剂的比表面积和孔体积随着W含量的增加先增大后减小；强酸量和总酸量都随W含量的增加有明显增加；W的加入使得催化剂表面的 Ni^δ+含量有所降低，而 P^δ-含量有所增加；在大于360℃时，催化剂对二苯并噻吩具有很好的深度加氢脱硫活性，并且以直接脱硫生成联苯的脱硫机理为主。

Influence of W on Structure and Hydrodesulfurization Performance of Ni2P/SBA-15 Catalysts

Ni₂P/SBA-15 precursors were prepared by co-impregnation method with nickel nitrate as nickel source, ammonium hydrogen phosphate as phosphorus and mesopore molecular sieve SBA-15 as support. Then the W was introduced into the precursors and the W-Ni₂P/SBA-15 precursors were converted into corresponding W-Ni₂P/SBA-15 catalysts after temperature-programmed reduction in flowing H₂. The structure of W-Ni₂P/SBA-15 was characterized by XRD, N₂ adsorption-desorption isotherms, NH₃-TPD, and XPS. The catalytic activity of W-Ni₂P/SBA-15 for the hydrodesulfurization of dibenzothiophene was evaluated. The result showed that only Ni₂P phase was formed in the W-Ni₂P/SBA-15 . The specific surface area and the pore volume of W-Ni₂P/SBA-15 increased then decreased when W content increased. Both the stronger acid sites and the total acid amount of W-Ni₂P/SBA-15 obviously increased with the increase of W content, and so did the Ni^δ+ and the P^δ- content  of the catalyst surface. W-Ni₂P/SBA-15 catalysts exhibited good catalytic performance of deep hydrodesulfurization of dibenzothiophene over 360℃, in which the direct desulfurization was the main desulfurization mechanism.