Reactive Grinding synthesis of La(Sr,Ce)CoO3 and their properties in toluene catalytic total oxidation

Abstract

AbstractPerovskites‐type metal oxides are an attractive alternative to noble metal‐based materials for environmental catalysis. Nevertheless, they suffer from major issues such as unattractive textural properties and lower intrinsic activities than those of noble metal counterparts. Reactive grinding (RG) has been already proved to be a powerful method to produce materials with improved textural properties. La1‐xA’xCoO3 (A’: Sr, Ce) perovskite‐type materials were synthesized by RG synthesis as a 3‐steps top down method: (i) conventional solid‐state reaction – SSR (leading to microcrystalline material); (ii) high energy ball milling – HEBM and (iii) low energy ball milling – LEBM. The physicochemical properties of perovskite materials were investigated by XRD, N2‐physisorption, H2‐TPR, O2‐TPD and XPS, while their catalytic performances were evaluated for the toluene total oxidation reaction. In this study we showed that the HEBM step leads in a drastic reduction in crystal size to nanometric scale along with aggregation into dense particles. The LEBM step allows the deagglomeration of particles and specific surface areas were significantly increased. Their performances in the toluene total oxidation increased along grinding steps and a maximum of catalytic performance was observed for La0.9Sr0.1CoO3. This material also exhibited a high catalytic stability as a function of the reaction time, under dry and wet air reaction conditions.