High Surface Area Ceria Nanoparticles via Hydrothermal Synthesis Experiment Design

Abstract

Hydrothermal synthesis of CeO2was optimized on two reactant concentrations and synthesis temperature and duration, in order to achieve material having the greatest specific surface area (SSA). Taguchi method of experimental design was employed in evaluation of the relative importance of synthesis parameters. CeO2nanoparticles were characterized using X-ray diffraction, nitrogen adsorption-desorption isotherms, and scanning electron microscopy. Optimum conditions for obtaining particles with greater SSA were calculated according to Taguchi’s model “the-higher-the-better.” Synthesis temperature was found to be the only parameter significant for enabling nanoparticles with greater SSA. Mesoporous nanocrystalline ceria with SSA as great as 226 m2 g−1was achieved, which is unprecedented for the hydrothermally synthesized ceria. The reason for this achievement was found in temperature dependence of the diffusion coefficient which, when low, favors nucleation yielding with fine particles, while when high it favors crystal growth and formation of one-dimensional structures. The occurrence of 1D-structure in sample exhibiting the smallest SSA was confirmed. Very fine crystallites with crystallite size as low as 5.9 nm have been obtained being roughly inverse proportional to SSA. Selected samples were tested as catalyst for soot oxidation. Catalyst morphology turned out to be decisive factor for catalytic activity.

Phase composition, morphology, properties and improved catalytic activity of hydrothermally-derived manganese-doped ceria nanoparticles

“…Three cycles involving sonification in an ultrasonic bath and centrifugation were performed to obtain a pure sample. The details of the synthesis procedure have been published elsewhere [28]. Finally, the product was dried at 60 °C and thermally treated at 500 °C for 2 h. The thermal treatment has been performed since the catalyst nanoparticles are expected to work at elevated temperatures.…”

Brief review on carbon derivatives based ternary metal oxide composite electrode materials for lithium-ion batteries

“…Electron beam lithography [18], Aerosol spray [19], Gas-phase condensation [20], and Ball milling [21] are some of the techniques that fall under the top-down approach. The bottom-up synthesis strategy of nanomaterials derived from atoms or molecules includes Hydrothermal [22], Co-precipitation [23], Ultrasonication [24], Sol-gel [25], Electrodeposition [26] and Combustion [27] methods.…”