Characterization and cataytic properties of supported nickel molybdenum nitrides for hydrodenitrogenation

摘要

The characterization and hydrodenitrogenation activity of 3-methyl pyridine have been obtained. The results from the characterization techniques (X-ray diffraction (XRD), temperature-prograrnmed reaction (TPR) and XPS) were used to illustrate the structure, surface reduction propertie;sand the role of Ni metal in the reaction. The NiMoNx/-Y-Al_2O_3 cat- alyst is more active than a MO_2N/'Y-Al_2O_3 catalyst with the same MOO3 loading. MO_2N, Ni_3Mo_3N and Ni metal are formed in the NiMoNx/'Y-Al_2O_3 catalyst; moreover, the synergy among them is probably responsible for the high activ- ity of NiMoNx/'Y-Al_2O_3 catalyst. The addition of Ni metal enhances the reducibility of Mo_2N/'Y-Al_2O_3 phase and also promotes the HDN activity. The reasons for reduction before reaction and the surface ion state changes during reduction are illustrated by XPS techniques.