Time-resolved study on dynamic chemical state conversion of SiO2-supported Co species by means of dispersive XAFS technique

16th International Conference on X-ray Absorption Fine Structure

Chotiwan, S.^1 ; Tomiga, H.^1 ; Yamashita, S.^1 ; Katayama, M.^1 ; Inada, Y.^1

Department of Applied Chemistry, Ritsumeikan University, Kusatsu

525-8577, Japan^1

关键词: Intermediate formation;    Oxidation reactions;    Oxidative environment;    Particle dispersion;    Relative stabilities;    Temperature programmed;    Time resolved measurement;    Time resolved studies;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/712/1/012061/pdf
DOI  :  10.1088/1742-6596/712/1/012061

来源: IOP

【 摘 要 】

The chemical state conversion of the Co species supported on SiO2was investigated using the in-situ and the time-resolved XAFS techniques. The supported Co3O4species was finally reduced to metallic Co with the stable intermediate state of CoO for both the temperature-programmed and time-course processes. The oxidation of Co0traced the reverse route to Co3O4, whereas the relative stability of the Co3O4species to the CoO intermediate under the oxidative environment diminished the composition of CoO. The time-resolved measurement for the oxidation reaction showed an additional intermediate at the early stage of the CoO intermediate formation suggesting the Co0particle dispersion.