Rare earth hydroxycarbonate materials with hierarchical structures: Preparation and characterization, and catalytic activity of derived oxides

• Published in: Solid state sciences Vol. 10; no. 8; pp. 1028 - 1036
• Main Authors: Zhao, Daoli, Yang, Qing, Han, Zhaohui, Sun, Fengyan, Tang, Kaibin, Yu, Fei
• Format: Journal Article
• Language: English
• Published: Paris Elsevier Masson SAS 01.08.2008; Elsevier
• Subjects: Catalysis; Catalysts; Catalysts: preparations and properties; Chemical synthesis methods; Chemistry; Cross-disciplinary physics: materials science; rheology; Crystal morphology; Exact sciences and technology; General and physical chemistry; Hydrothermal crystal growth; Materials science; Methods of nanofabrication; Nanoscale materials and structures: fabrication and characterization; Phosphors; Physics; Quantum wires; Rare earth compounds; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Catalysts; Crystal morphology; Rare earth compounds; Phosphors; Hydrothermal crystal growth; Crystal growth; Temperature dependence; Catalytic reaction; Stacking sequence; Fluorescence; Dysprosium; Materials preparation; Hydrothermal growth; Hydrothermal synthesis; Dumbbell model; Carbon monoxide; Catalyst activity; Nanorod; Nanostructured materials; Nanomaterial synthesis
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2007.11.019

A hydrothermal process is reported for the preparation of rare earth hydroxycarbonates LnOHCO 3 (Ln = Pr, Sm, Dy, Y) with hierarchical structures, such as dumbbell nanorod clusters, stacked lamellae and patched rods. All the hydroxycarbonate samples show fluorescence, and the emission wavelengths and intensity may be different for different samples. The hydroxycarbonate samples are generally stable under 380 °C, but will decompose to the respective oxides at higher temperatures. The oxides are tested for catalytic conversion of carbon monoxide to carbon dioxide. It reveals that all the rare earth oxides are active to the catalytic reaction, and Sm 2O 3 shows superior catalytic performance to the other oxides. Rare earth hydroxycarbonates' LnOHCO 3 (Ln = Pr, Sm, Dy, Y) superstructures have been synthesized through a hydrothermal process. The materials with hierarchical structures are assembled from anisotropic subunits, and the reaction and growth mechanisms of the lanthanide hydroxycarbonates along with their luminescent properties have been investigated using techniques of XRD, SEM, TEM, FESEM, ED, IR, TGA and PL. The derived rare earth oxides from the hydroxycarbonates are firstly investigated for the catalytic conversion of carbon monoxide to carbon dioxide, showing effective catalytic performance at relatively low temperature. [Display omitted]