The role of nickel in pyridine hydrodenitrogenation over NiMo/Al2O3

Al2O3 supported Mo, Ni, and NiMo/Al2O3 catalysts with various Ni contents were prepared to investigate the role of Ni as a promoter in a NiMo bimetallic catalyst system. The hydrodenitrogenation (HDN) reaction of pyridine as a catalytic probe was conducted over these catalysts under the same reaction conditions and the catalysts were characterized using BET surface area measurement, infrared spectroscopy, temperature programmed reduction, DRS and ESR. According to the results of reaction experiments, the NiMo/Al2O3 catalyst showed higher activity than Mo/Al2O3 catalyst in the HDN reaction and particularly the one with atomic ratio [Ni/Ni+Mo)l=0.3 showed the best activity for the HDN of pyridine. The findings of this study lead us to suggest that the enhance ment in the HDN activity with nickel addition could be attributed to the improvement in the reducibility of molybdenum and the formation of Ni-Mo-O phase.