COMPARATIVE HYDRODENITROGENATION ACTIVITY OF MOLYBDENUM, CO-MO AND NI-MO ALUMINA-SUPPORTED CATALYSTS

The hydrodenitrogenation of pyridine is studied under high hydrogen pressure with and without sulfur in the gas phase on three alumina-supported catalysts: molybdenum, Ni-Mo and Co-Mo. Without sulfur, the three catalysts exhibit the same activity. In the presence of sulfur Ni-Mo is 2.5 more active than molybdenum and Co-Mo. Because of the design of the experiment, a full analysis of the reaction products is possible and shows that the difference of activity between the catalysts depends on the difference of acidity of their surfaces. A description on this difference is proposed.