NiMoP/Al2O3催化剂上柠檬酸促进喹啉加氢脱氮性能研究

在NiMoP浸渍液中添加不同量的柠檬酸，负载在氧化铝载体上制备了系列NiMoP-C(x)（x表示浸渍液中羧酸与Ni的摩尔比）加氢催化剂。将该类催化剂应用于喹啉加氢脱氮反应中，表现出了较高的催化活性，其中NiMoP-C(4)催化剂的加氢脱氮活性最高。用XRD，H2-TPR，HRTEM，XPS技术对系列催化剂进行了表征，XRD结果表明柠檬酸未影响活性组分在载体表面的分散，H2-TPR结果表明柠檬酸使得催化剂的低温还原峰向低温方向迁移，HRTEM结果表明柠檬酸的加入使MoS2颗粒的堆积层数增加，活性组分进入载体体相的比例降低，进一步优化了活性组分与载体的表面相互作用，XPS结果表明柠檬酸的加入降低了Ni与载体间的相互作用，提高了Ni的硫化程度和有效利用率，延缓了Ni的硫化，促进了边缘镶嵌Ni原子的MoS2颗粒的形成，增加了催化剂表面的活性位数量，提高了催化剂的活性。

INFLUENCE OF CITRIC ACID ON QUINOLINE HYDRODENITROGENATION OF NiMoP/Al2O3 CATALYSTS

A series of NiMoP-C(x) catalysts was prepared with alumina support by adding different amounts of citric acids in NiMoP impregnating solutions. These catalysts exhibited high catalytic activity in hydrodenitrogenation reaction of quinolone and were analyzed with XRD, TPR and HRTEM techniques. XRD and TPR results showed that the active component dispersions on the surface of carrier were not affected by citric acid but their low temperature reduction peak moved to the lower temperature. HRTEM analysis indicated that citric acid increased the accumulation degree of MoS2 particles, reduced the proportion of active components entering the carrier phase, and further optimized the surface interaction between the active component and the carrier. XPS analysis showed that the interaction between Ni and carrier was reduced, resulting in improvement of the sulfidation degree of Ni and its effective utilization, the sulfidation of Ni was delayed, which promotes the formation of MoS2 particles with Ni atoms embedded in the edge. The addition of citric acid increased the number of active site on the surface of the catalyst, and further improved the activity of the catalyst.