2019 Volume 21 Pages 19-22
The chemical state conversion of the Ni species supported on SiO2 has been analyzed by in situ XAFS measurements. The composition change by the gas switch from H2 to O2 for the partially reduced NiO particles indicates that the metallic Ni(0) species exists at both the particle surface and the inner core. In addition, the analysis on the reduction property suggests that the oxidized Ni species is located at the adjacent place to the metallic Ni(0) species. It is concluded that the metallic Ni(0) and NiO species are heterogeneously distributed in the Ni particle under the reaction condition. The reduction of the NiO particle was initiated at the highly reactive spots and was expanded peripherally. This study achieved to find out the detailed reduction mechanism of the NiO particle supported on SiO2.
