Soft‐Chemistry Synthesis, Characterization, and Stabilization of CGO/Al ₂ O ₃ /Pt Nanostructured Composite Powders

Abstract

Soft‐chemistry routes were used to synthesize Ce 0.9 Gd 0.1 O 1.95 ‐based powders with attractive and stable structural, morphological, and textural properties. In the intermediate temperature range between 500° and 700°C, the average Gd‐doped CeO 2 (CGO) crystallite size is in the range 9–22 nm and the specific surface area varies from 43.4 to 8 m 2 /g. Above 700°C, a phase separation occurs between ceria and gadolinium oxide. Addition of alumina was found to be useful in stabilizing the CGO nanocrystallites at a high temperature and to avoid phase separation. A homogeneous dispersion of Pt nanoparticles (<10 nm at 1000°C) in the CGO materials was found to be possible by post‐impregnation, although direct insertion of the Pt precursors during the synthesis led to aggregated particles, with less potential for catalytic applications.