XAFS Analysis on Reduction Process of Ni Supported on Rutile TiO₂

Abstract

The effect of the calcination and reduction treatment on the chemical state of the Ni species supported on TiO₂ was revealed by the XRD and XAFS method. The TiO₂-supported Ni catalyst calcined at various temperatures was characterized by the XRD measurements. It is revealed that the NiO species was incorporated into TiO₂ support as the species of NiTiO₃, when the calcination temperature was higher than 600 °C. The chemical state conversion of the Ni species during the temperature programmed reduction process was investigated by in situ XAFS measurements. The reduction of NiTiO₃ proceeded below 700 °C, and the metallic Ni(0) species was generated on TiO₂. The reduction temperature was higher than that of NiO on TiO₂.