Physico-chemical investigation of catalytic oxidation sites in 4%Rh/CeO2 catalysts prepared by impregnation and deposition–precipitation methods - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Chemical Physics Année : 2019

Physico-chemical investigation of catalytic oxidation sites in 4%Rh/CeO2 catalysts prepared by impregnation and deposition–precipitation methods

Résumé

4 wt % Rh/CeO2 catalysts were prepared by two different methods: deposition-precipitation (DP) and impregnation (Imp). X-ray diffraction (XRD), differential scanning calorimetry and thermogravimetry (DSC-TG), temperature-programmed reduction (TPR), and electron paramagnetic resonance (EPR) were used for physicochemical characterization. The solids were tested in propylene and carbon black oxidation reactions. The 4%Rh/CeO2 (DP) showed better catalytic performance in both reactions compared to the catalyst prepared by the impregnation method. The XRD technique evidenced the formation of Rh2O3 phase in the DP-solid after calcination of this latter at 400 °C for 4 h. EPR evidenced, only in the DP-solid, the presence of O2- species in interaction with the CeO2 surface whereas Rh4+ ions in the form of clusters were identified in both solids. The TPR technique showed that the DP-solid was reduced by hydrogen at lower temperature compared to the impregnated one. The higher catalytic performance of the DP-solid was attributed to the presence of O2- species along with the presence of Rh2O3 phase in ceria and to the better reducibility and lower particle size of the rhodium species.
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hal-03488251 , version 1 (20-12-2021)

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Paternité - Pas d'utilisation commerciale

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Madona Labaki, Samer Aouad, Sara Hany, Cynthia Abou Serhal, Edmond Abi-Aad, et al.. Physico-chemical investigation of catalytic oxidation sites in 4%Rh/CeO2 catalysts prepared by impregnation and deposition–precipitation methods. Chemical Physics, 2019, 527, pp.110472. ⟨10.1016/j.chemphys.2019.110472⟩. ⟨hal-03488251⟩
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