Guan Naijia

Characterization and catalytic properties of supported nickel molybdenum nitrides for hydrodenitrogenation

Abstract 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 NiMoN x /γ-Al 2 O 3 catalyst is more active than a Mo 2 N/γ-Al 2 O 3 catalyst with the same MoO 3 loading. Mo 2 N, Ni 3 Mo 3 N and Ni metal are formed in the NiMoN x /γ-Al 2 O 3 catalyst; moreover, the synergy among them is probably responsible for the high activity of NiMoN x /γ-Al 2 O 3 catalyst. The addition of Ni metal enhances the reducibility of Mo 2 N/γ-Al 2 O 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.

One-Pot Synthesis of Visible-Light-Responsive TiO2 in the Presence of Various Amines

Abstract Visible-light-responsive TiO2 catalysts were prepared using a one-pot method at low temperatures in different amine systems, using TiCl3 as the precursor. The as-synthesized TiO2 powders were characterized using X-ray diffraction, ultraviolet-visible absorption spectroscopy, elemental analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results reveal that the absorption onset of the as-synthesized TiO2 powders red-shifted to the visible region and that the ethylenediamine system was clearly superior to the triethylamine and diethylamine systems. The nitrogen atoms were located at the oxygen site in the TiO2 lattice to form an O-Ti-N structure in the ethylenediamine synthetic system. Phenol degradation was used as a probe reaction to evaluate the photocatalytic activity of nitrogen-doped TiO2; 97.88% phenol was degraded after reaction for 6 h under visible-light irradiation.