Abstract: 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.

Key words: citric acid, quinoline, hydrodenitrogenation, catalyst