Core-shell Nanostructured Nanopowders along (CeOx)x(Al2O3)1-x Tie-Line by Liquid-Feed Flame Spray Pyrolysis (LF-FSP)

We report here the synthesis of (CeOx)(1-x)(Al2O3) mixed-metal oxide nanopowders with molar ratios that span the CeOx-Al2O3 composition range. Liquid-feed flame spray pyrolysis (LF-FSP) of mixtures of N(CH2CH2O)(3)Al (alumatrane) and Ce(O2CCH2CH3)(OH) precursors dissolved in ethanol were aerosolized with O-2, combusted at temperatures of 1500-2000 degrees C and rapidly quenched thereafter to provide (CeOx)(1-x)(Al2O3)(x) nanopowdcrs of selected compositions. All powders exhibit average particle sizes (APSs) < 20 nm and corresponding surface areas of >= 50 m(2)/g when produced at rates of 100-300 g/h. The as-processed powders were characterized in terms of phase, size, specific surface area, composition, and morphology by BET, XRD, XRF, SEM, TEM, STEM, XEDS, XPS, FT-IR, and TGA-DTA. Surprising core-shell nanostructured nanopowders are observed in the Ce-Al-O system at CeOx rich concentrations (>= 15 mol %). In addition, evidence is presented for the incorporation of Ce (3+) ions in the delta-alumina lattice at the lowest concentrations and Ce-magnetoplumbite (CeAl11O18) at 5-10 mol % CeOx concentrations.