硫化行为对Ni2P/SBA-15催化剂结构和加氢脱硫性能的影响

以介孔分子筛SBA-15为载体、硝酸镍为镍源、磷酸氢二铵为磷源,等体积浸渍法制备了Ni2P/SBA-15催化剂前驱体,然后在H2流中程序升温还原,得到Ni2P/SBA-15催化剂,再用CS2溶液对催化剂进行了硫化处理,制备出了硫化态xCS2-Ni2P/SBA-15催化剂。采用XRD、N2吸附-脱附、XPS对催化剂的结构进行了表征,对催化剂的二苯并噻吩加氢脱硫活性进行了评价,考察了硫化条件对催化剂结构和二苯并噻吩加氢脱硫催化活性的影响。结果表明,xCS2-Ni2P/SBA-15催化剂的物相有Ni2P、Ni12P5、Ni3S2,催化剂的比表面积随硫化溶液中CS2质量分数的增加有一定程度的增加,催化剂表面的Ni以Niδ+和Ni 2+形式存在,P以Pδ-和P5+形式存在。采用5%CS2硫化溶液硫化的催化剂对二苯并噻吩加氢脱硫具有最高的催化活性,380℃时二苯并噻吩的转化率可达99.3%。硫化过程形成的Ni3S2活性物相对二苯并噻吩的转化和直接脱硫都有利。

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

A series of xCS₂-Ni₂P/SBA-15  catalysts were prepared with Ni(NO₃)₂ as Ni source, (NH₄)₂HPO₄ as P source, SBA-15 as a support and CS₂ as a sulfurization reagent. The structures of the catalysts were characterized by XRD, N₂ adsorption-desorption and XPS. The hydrodesulfurization (HDS) activities of the catalysts were evaluated by using dibenzothiophene (DBT) as a model compound. The effects of the sulfurization condition on the structure and catalytic activity of the catalyst were investigated. The results indicated that the phases of Ni₂P, Ni₁₂P₅ and Ni₃S₂ existed in xCS₂-Ni₂P/SBA-15 catalysts. BET surface area of  xCS₂-Ni₂P/SBA-15 catalysts increased with the CS₂ mass fraction in sulfurization solution. Ni existed in the Ni^δ+ and Ni²⁺ species and P existed in the P ^δ- and P ⁵⁺ species on the catalyst surface. xCS₂-Ni₂P/SBA-15 catalyst sulfided with the solution of 5%CS₂ exhibited the best catalytic performance for DBT HDS reaction, in which the conversion of DBT reached 99.3% at 380℃. Ni₃S₂ phase played an important role on DBT conversion and direct desulfurization.