金属助剂对Ni2P/SBA-15催化剂结构及二苯并噻吩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，采用共浸渍法制备了 P/Ni 摩尔比为0.8的 Ni₂P/SBA-15催化剂，然后添加 Li、Na、K、Mg、Ca、Sr 和 Ba 等金属助剂，制备了一系列不同金属助剂的M-Ni₂P/SBA-15(其中M为 Li、Na、K、Mg、Ca、Sr 和 Ba)催化剂。采用 XRD 对该系列催化剂的结构进行了表征，并以二苯并噻吩质量分数为1%的二苯并噻吩/十氢萘溶液为模型化合物，在微型固定床反应器上评价它们的加氢脱硫(HDS)性能。结果表明，M-Ni₂P/SBA-15催化剂的活性相为 Ni₂P。不同的金属助剂对催化剂性能的促进作用不同，其中碱土金属Ca能够明显地提高 Ni₂P/SBA-15催化剂的 HDS 活性，Ca 质量分数为3.5%的Ca-Ni₂P/SBA-15催化剂的 HDS 活性最好。在反应压力3.0 MPa、反应温度360℃的条件下，3.5%Ca-Ni₂P/SBA-15催化剂催化的二苯并噻吩 HDS 的转化率达到98.6%。不同金属助剂以不同方式影响加氢脱硫反应的机理。  

Effect of Metal Promoters on the Structure and Performance of the Ni2P/SBA-15 Catalyst for Hydrodesulfurization

Ni₂P/SBA-15 catalysts with initial P/Ni molar ratio of 0.8 were prepared by co impregnation method with mesoporous molecular sieve SBA-15 as support, Ni(NO₃)₂·6H₂O as a source of nickel and (NH₄)₂HPO₄ as a source of phosphorus. Then, a series of M-Ni₂P/SBA-15 catalysts were prepared by the addition of Li, Na, K, Mg, Ca, Sr, Ba metal promoters and characterized by X-ray diffraction(XRD). The catalytic performance of the catalysts for hydrodesulfurization(HDS) was evaluated in a fixed bed microreactor with the decalin solution of 1% (mass fraction) model compound dibenzothiophene. The results indicated that Ni₂P particles were the active phase for M-Ni₂P/SBA-15 catalysts. Different metal promoters (M) had different effects on the HDS performance of M-Ni₂P/SBA-15 catalysts, among which the alkaline earth metal Ca was the best one to improve the HDS activity of the catalysts. Over the Ca-Ni₂P/SBA-15 catalyst with Ca mass fraction of 3.5% the conversion of DBT HDS reached 98.6% under the conditions of reaction pressure at 3.0 MPa and temperature at 360℃. In addition, different metal promoters also affect HDS reaction mechanism in different ways.