| Autor: |
Delporte, Maxime, Cavailles, Julie, Martin Romo y Morales, Michaël, Bion, Nicolas, Nodari, Luca, Courtois, Xavier, Can, Fabien, Kaper, Helena |
| Zdroj: |
Inorganic Chemistry; 20220101, Issue: Preprints |
| Abstrakt: |
In the present work, a series of CaTi1–xFexO3−δ(0 < x< 0.5) materials are prepared using a modified Pechini method based on citric acid and a polyol as chelating agents. The synthesis conditions are optimized with respect to the specific surface area and phase purity by varying polyols (ethylene glycol, glycerol, and 1.6-hexanediol) and the ratio between citric acid, polyols, and cations. The impact of the polyols and the iron content (up to 40 mol % on the B site) is studied with respect to the oxygen exchange rate, reducibility using H2-TPR, and catalytic performance for methane total oxidation. A correlation between the oxygen exchange rate studied using 18O exchange in powdered samples of CaTi1–xFexO3−δ(0 < x< 0.5) and ferric sites determined using Mössbauer spectroscopy and H2-TPR is established. The oxygen activation and diffusion in CaTi1–xFexO3−δ(0 < x< 0.5) continuously increase in the studied range of Ti substitution. The methane oxidation performance does not increase above x= 0.3, showing that methane oxidation is not limited by surface oxygen activation and CH4is activated by specific iron sites in Fe-doped perovskites. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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