Ce–Zr-Sm ternary oxides synthesized via a template free urea-hydrothermal method. Issue 18 (15th September 2022)

• Record Type: Journal Article
• Authors: Suarez Anzorena, Rosario; Muñoz, Fernando F.; Toscani, Lucía M.; Bonelli, Pablo; Cukierman, Ana Lea; Larrondo, Susana A.
• Is Part Of: Ceramics international. Volume 48:Issue 18(2022)
• Page Start: 25714
• Page End: 25722
• Publication Date: 2022-09-15
• Subjects: CeO2 -- ZrO2 -- Sm2O3 -- Hydrothermal -- XAS; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.05.243
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Nano-crystalline Ce0.9 Zr0.1-x Smx O2-δ (0 ≤ x ≤ 0.10) mixed oxides were synthesized for the first time by a urea-hydrothermal method without the use of template or structure directing agents. The use of a high molar ratio of urea to metal cations and temperature reaction ensures the formation of a single-phase homogeneous ternary solid solution. The (NH4 )2 Ce(NO3 )6 precursor, in a greater proportion, together with urea acts as a structure directing agent towards the completion of a self-assembly shuttle to dumbbells to sphere sequence. The analysis of the obtained morphologies has demonstrated that the physicochemical nature of the doping precursor in solution has a strong influence on the final morphology without losing morphological control. Thus, the ZrO(NO3 )2 precursor favors the formation of cauliflower-type particles whereas Sm(NO3 )3 favors the formation of spheres. As a result, the morphology of the samples evolves from cauliflowers to spheres as Sm content increases in the mixed oxides, with a great effect on the high specific surface area (80–115 m 2 .g −1 ) and total pore volume (0.109–0.315 cm 3 .g −1 ) obtained in all cases. Solids reduce in three stages reaching high reduction percentages (≈50%). Graphical abstract: Image 1