a1 Institute of Process Engineering, ETH Zürich, CH-8092 Zürich, Switzerland
Flame spray pyrolysis (FSP) has been used to synthesize high-surface-area ceria from cerium acetate in acetic acid solution. With the addition of an iso-octane/2-butanol mixture to that solution, homogeneous CeO2 nanoparticles were obtained. The specific surface area of the powders ranged from 240 to 101 m2/g by controlling the oxygen dispersion and liquid precursor flow rates through the flame. Furthermore, for production rates from 2 to 10 g/h a constant average primary particle size could be obtained at selected process parameters. The ceria showed high crystallinity and primary particles with a stepped surface. The powder exhibited good thermal stability and conserved up to 40% of its initial specific surface area when calcinated for 2 h at 900 °C. This shows the potential of FSP made ceria for high-temperature applications as in three-way catalysts or fuel cells.
(Received January 11 2002)
(Accepted March 12 2002)