镍助剂对碳化钼催化剂的二苯并噻吩加氢脱硫性能的影响

Effect of Ni Promoter on Dibenzothiophene Hydrodesulfurization Performance of Molybdenum Carbide Catalyst

将MoO3和Ni-Mo混合氧化物在CH4/H2气氛中程序升温还原碳化制备了相应的碳化钼和碳化镍钼催化剂,X射线粉末衍射表征其物相分别为-βMo2C和Ni-Mo2C.考察了Ni助剂对碳化钼催化剂的制备及二苯并噻吩加氢脱硫反应性能的影响.结果表明,Ni助剂的加入降低了碳化钼催化剂所需的还原碳化温度,提高了催化剂的比表面积,并对其二苯并噻吩加氢脱硫反应活性有明显的促进作用.Ni助剂添加量以Ni/Mo原子比为0.3为宜,此时Ni和Mo之间的催化协同效应达到最佳.当反应压力为3.0 MPa,反应温度为330℃,空速8 h-1,H2/原料液体积比为500∶1时,625℃还原碳化制备的碳化镍钼催化剂对0.6%二苯并噻吩/环己烷溶液的二苯并噻吩转化率达到96.25%,较相应的碳化钼催化剂提高了1.57倍.

Molybdenum carbide and nickel-molybdenum carbide catalysts were prepared by temperature-pro- grammed reduction using a CH4/H2 gas mixture to carburize molybdenum trioxide and nickel-molybdenum oxide. X-ray diffraction patterns showed that the crystals were β-Mo2C and Ni-Mo2C, respectively. The effects of nickel promoter on the preparation of molybdenum carbide and its catalytic performance for hydrodesulfurization of dibenzothiophene （DBT） were studied. The results indicated that adding a proper amount of the nickel promoter could decrease the carburizing temperature, increase the BET surface area, and markedly promote the DBT hydrodesulfurization activity of the molybdenum carbide catalysts. When the Ni/Mo atom ratio was 0.3, the synergistic interaction between Ni and Mo was the maximum. The hydrodesulfurization conversion of DBT over the Ni-Mo2C catalyst reached 96.25% under the reaction conditions of 330 12 , 3.0 MPa, and space velocity 8 h^-1, and the conversion was 1.57 times higher than that of Mo2C.