Synthesis and catalytic properties of microemulsion-derived cerium oxide nanoparticles

• Published in: Journal of solid state chemistry Vol. 181; no. 7; pp. 1614 - 1620
• Main Authors: Kockrick, Emanuel, Schrage, Christian, Grigas, Anett, Geiger, Dorin, Kaskel, Stefan
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.2008
• Subjects: ANNEALING; CATALYSIS; Ceria nanoparticles; CERIUM HYDROXIDES; CERIUM NITRATES; CERIUM OXIDES; COMBUSTION; Dynamic light scattering; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; Inverse microemulsion; LIGHT SCATTERING; MICROEMULSIONS; NANOSTRUCTURES; PARTICLE SIZE; PARTICLES; PRECIPITATION; SMALL ANGLE SCATTERING; Small angle X-ray scattering; Soot combustion; SYNTHESIS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION; Soot combustion; Inverse microemulsion; Catalysis; Ceria nanoparticles; Dynamic light scattering; Small angle X-ray scattering
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2008.04.036

The synthesis of cerium dioxide nanoparticles using an inverse microemulsion technique and precipitation method was investigated. Cerium hydroxide nanoparticles were synthesized by adding diluted ammonia to n-heptane–surfactant–cerium nitrate system. The micelle and particle size in the range of 5–12 nm were controlled by varying the molar water to surfactant ratio and analyzed by dynamic light scattering (DLS), small angle X-ray scattering (SAXS) and high-resolution transmission electron microscopy (HRTEM). Cerium hydroxide nanoparticles were isolated and subsequently treated at 100–600 °C to obtain nanoscale ceria. Crystallite sizes of cerium dioxide in the range of 6–16 nm were estimated by Scherrer analysis by X-ray diffraction (XRD) and HRTEM. The catalytic activity of particles annealed at 400 and 600 °C in soot combustion reactions was characterized by temperature-programmed oxidation (TPO) indicating a size-dependant activity. Crystallite sizes and catalytic stability of elevated ceria systems were tested in second combustion cycles. The synthesis of cerium dioxide nanoparticles using an inverse microemulsion technique and precipitation method was investigated using small angle X-ray scattering, dynamic light scattering and high-resolution transmission electron microscopy. Catalytic activity of ceria nanoparticles was tested in soot combustion reaction indicating size-dependent reactivity.