Synthesis of Nanocrystalline CeO₂−ZrO₂ Solid Solutions by a Citrate Complexation Route: A Thermochemical and Structural Study

Abstract

The synthesis of nanocrystalline solid solutions of general formula Ce x Zr1−x O2 (x = 0.1, 0.25, 0.5, 0.75, and 0.9) using a citrate complexation technique was followed with thermochemical methods, and the resulting powders were characterized using X-ray diffraction (XRD) and electron microscopy (scanning electron microscopy and high-resolution transmission electron microscopy (HRTEM)). Qualitative analysis of XRD data indicated that the samples exhibited either a cubic (Fm3m) or a tetragonal (P42/nmc) phase, depending on CeO2 content. Electron diffraction results were consistent with the XRD findings. In HRTEM, the internal crystal structure of the nanoparticles was observed to be highly ordered and primary particle size data were collected. Average crystallite size, obtained from the XRD data, was 4.8−8.3 nm, with the larger values at the compositional extremes. A similar trend was observed in HRTEM, although values were generally slightly higher. The Ce0.5Zr0.5O2 solid solution had the smallest crystallites (4.8 nm) and the highest specific surface area (45.8 m2·g−1).

Focus on the modified CexZr1−xO2 with the rigid benzene-muti-carboxylate ligands and its catalysis in oxidation of NO

“…From the SAED patterns ( Fig. 2(D3 and E3)), the pseudocubic structure could be identified [19,36]. Notably, the (1 1 1) plane was predominate in all samples.…”

Comparative Study on Nano-Sized 1 wt% Pt/Ce0.8Zr0.2O2 and 1 wt% Pt/Ce0.2Zr0.8O2 Catalysts for a Single Stage Water Gas Shift Reaction

“…The product gas was chilled, passed through a trap to condense the residual water, and then analyzed on-line using an Agilent micro-gas chromatograph. [32] reported that nano-crystalline ceria-zirconia solid solution exhibited either cubic or tetragonal phase depending upon CeO 2 content. They applied Rietveld refinement method to know the phases present in the nano crystalline ceria-zirconia solid solution.…”

Humidity Related Low Temperature Conductivity Hysteresis of Ce1–xZrxO2 (0 ≤ x ≤ 1) Ceramics. Structural Disorder Relationship

“…These anodes were prepared as porous metal-ceramic composites, using optimized Ni charges and high surface Ce/Zr supports prepared at relative low temperatures, T ≤ 1,273 K. However, the crystal structure of low temperature prepared samples could differ considerably from that of high temperature phases prepared in this work, where Ce and Zr dilution is favored at high temperatures in intermediate compositions, improving the OSC behavior. The segregation of tetragonal Zr-rich and cubic Ce-rich phases, produced at low temperatures [31,32], could severely affect the reforming performances of electrodes used in SOFC's devices.…”