Reduction Behavior of CeO₂−ZrO₂ Solid Solution Prepared from Cerium Zirconyl Oxalate

Abstract

CeO 2 -ZrO 2 solid solutions were prepared by means of thermal decomposition of cerium zirconyl oxalate in an argon flow at 1273 K followed by oxidation at 673-873 K in air. The reduction behavior of the obtained CeO 2 -ZrO 2 powders was investigated and compared with the samples prepared by the other methods already reported to yield CeO 2 -ZrO 2 powders with high redox activity. The CeO 2 -ZrO 2 samples prepared from the oxalate showed excellent reduction behavior, despite their very low surface areas. The reason for the excellent oxygen evolution behavior of the powders was discussed, from the viewpoints of the structure and the preparation process, and was attributed to both the appearance of a cubic phase with a different oxygen arrangement and the reduction by carbon formed in the sample preparation process.

Synergy between gold and oxygen vacancies in gold supported on Zr-doped ceria catalysts for the CO oxidation

“…This trend agrees with the Vegard's law [38], and points out the high solubility of Zr 4+ cations in the CeO 2 network [14,32]. Some authors [39,40] have observed similar results establishing that, as the Zr content of the solid solution increases, the lattice parameters decrease.…”

“…The improvement of oxygen storage capacity, redox properties and oxygen mobility in ceria by the Ce 4+ /Zr 4+ isomorphous substitution, which is in good agreement with the TPR results presented in Figure 9, has been also reported [14,60]. Such enhancement of the redox properties in the mixed oxides also correlates with the strong interaction between Ce 4+ and Zr 4+ cations deduced by the XRD patterns and with the alteration of the symmetry observed through the Raman spectroscopy.…”

“…Besides this, Di Monte et al [1] [13] suggested that the increase of CeO 2 content in Ce X Zr 1-X O 2 mixed oxides produces the increase of BET area and solids with a ceria content superior than that of Ce 0.4 Zr 0.6 O 2 may be are candidates for low to medium temperature catalytic applications, avoiding the phase segregation. On the other hand, Masui et al [14] presented the synthesis of Ce 0.5 Zr 0.5 O 2 employing different experimental procedures and the evolution of a cubic pyrochlore-type structure was detected in some cases.…”

Fe-doped ceria solids synthesized by the microemulsion method for CO oxidation reactions

“…This band has not been previously discussed for Ce-Fe mixed systems, although similar ones have been described for Zr-doped CeO 2 solids. Masui et al [36] observed a Raman band around 307 cm -1 which they attributed to the formation of the tetragonal phase in the Zr-Ce mixed oxide. In a similar way, Fang et al [37] reported a band around 297 cm -1 in Ce-Zr and Ce-Gd mixed oxide systems due to the tetragonal phase formation in the solid solution.…”

Improvement of OSC performance for CeZrO4 solid solution with Al2O3 diffusion barrier

“…7), which has regularly-arranged Ce and Zr cations and slightly disordered oxygen [8]. Masui et al reported the OSC performance of the CeZrO 4 with the κ-phase was larger than that of the conventional CeZrO 4 [9]; hence the increase of the OSC-c of ACZ-H2-1000 up to the theoretical maximum could be attributed to the formation of this phase. In contrast to the OSC-c, the order of the OSC-r varied with the evaluation temperature.…”