Acta Phys. -Chim. Sin. ›› 1997, Vol. 13 ›› Issue (12): 1108-1114.doi: 10.3866/PKU.WHXB19971210

• ARTICLE • Previous Articles     Next Articles

EXAFS Studies on the Local Structure of Ni and Mo in Nickel-molybdenum Catalyst System

Han Ji-Hong,Xu Wei,Gu Chang-Xin,Hua Zhong-Yi,Niu Guo-Xing,Zhu Chong-Ye,Chen Hai-Ying,Li Quan-Zhi   

  1. Materials Science Department,Chemistry Department,Fudan University,Shanghai 200433
  • Received:1997-01-24 Revised:1997-08-16 Published:1997-12-15
  • Contact: Gu Chang-Xin

Abstract:

The local structure surrounding Mo and Ni atoms in a series of nickel-molybdenum-γ-Al2O3 catalysts promoted by P2O5 or TiO2 was investigated using EXAFS technique at Mo and Ni 1s edge. The analysis results show that the addition of P or Ti increases the metal dispersion under the condition of high Mo content and the octahedral structure in MoNiP catalysts is more abundant than that in MoNiTi. Moderate content of P2O5 facilitates the formation of the octahedral structure. It is also found that oxygen atoms of Mo-O bond in octahedral structure are easy to be substituted by S in hydrodesulphurization(HDS) reaction. In MoNiP catalysts the higher HDS activity might be caused by the abundance of octahedral structure.

Key words: EXAFS, Ti or P promoted nickel-molybdenum system, Hydrodesulphurization(HDS)