Characterization and catalytic properties of supported nickel molybdenum nitrides for hydrodenitrogenation

The characterization and hydrodenitrogenation activity of 3-methyl pyridine have been obtained. The results from the characterization techniques (X-ray diffraction (XRD), temperature-programmed reaction (TPR) and XPS) were used to illustrate the structure, surface reduction properties and the role of Ni metal in the reaction. The NiMoNx/gamma -Al2O3 catalyst is more active than a Mo2N/gamma -Al2O3 catalyst with the same MoO3 loading. Mo2N, Ni3Mo3N and Ni metal are formed in the NiMoNx/gamma -Al2O3 catalyst; moreover, the synergy among them is probably responsible for the high activity of NiMoNx/gamma -Al2O3 catalyst. The addition of Ni metal enhances the reducibility of Mo2N/gamma -Al2O3 phase and also promotes the KDN activity. The reasons for reduction before reaction and the surface ion state changes during reduction are illustrated by XPS techniques. (C) 2001 Elsevier Science B.V. All rights reserved.