RE0.6Zr0.4-xYxO2 (RE = Ce, Pr; X = 0, 0.05) solid solutions: An investigation on defective structure, oxygen mobility, oxygen storage capacity, and redox properties

H. He, H. X. Dai, K. W. Wong, Chak Tong AU*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

112 Citations (Scopus)

Abstract

We have examined the crystal structures, surface textures, oxygen mobility, oxygen storage capacity, and redox behaviors of RE0.6Zr 0.4-xYxO2 (RE=Ce, Pr; x=0, 0.05) solid solutions. According to the results of X-ray diffraction (XRD) studies, there are two cubic phases (Ce0.75Zr0.25O2, major; ZrO1.87, minor) in Ce0.6Zr0.4O2 (denoted as CZ hereafter) and Ce0.6Zr0.35Y 0.05O2 (CZY), but only one cubic phase in Pr 0.60Zr0.40O2 (PZ) and Pr0.60Zr 0.35Y0.05O2 (PZY). These nanosized materials are porous and have large surface areas. As revealed by the Ce 3d and Pr 3d results of X-ray photoelectron spectroscopic (XPS) investigations, the doping of Y3+ ions into the CZ and PZ lattices resulted in an increase in concentration of oxygen vacancies and Ce3+ and Pr4+ ions. The results of H2 (or CO)-O2 titration and temperature-programmed reduction (TPR)-reoxidation experiments indicate the presence of a reversible redox behavior of Ce4+/Ce3+ in CZY and Pr4+/Pr3+ in PZY. The results of 18O/16O exchange studies show that, with the presence of oxygen vacancies, the lattice O2- mobility on/in CZY and PZY enhanced. Based on such outcomes, we conclude that, by incorporating Y 3+ ions into CZ and PZ, one can enhance (i) lattice oxygen mobility, (ii) Ce3+ and Pr4+ concentrations, and (iii) oxygen uptake capacity. We observed that PZY is superior to CZY in redox behavior, oxygen mobility, and oxygen storage capacity.

Original languageEnglish
Pages (from-to)61-74
Number of pages14
JournalApplied Catalysis A: General
Volume251
Issue number1
DOIs
Publication statusPublished - 25 Sep 2003

Scopus Subject Areas

  • Catalysis
  • Process Chemistry and Technology

User-Defined Keywords

  • CeO-ZrO
  • PrO-ZrO
  • RE ZrYO ( RE=Ce, Pr; x=0, 0.05)

Fingerprint

Dive into the research topics of 'RE<sub>0.6</sub>Zr<sub>0.4-x</sub>Y<sub>x</sub>O<sub>2</sub> (RE = Ce, Pr; X = 0, 0.05) solid solutions: An investigation on defective structure, oxygen mobility, oxygen storage capacity, and redox properties'. Together they form a unique fingerprint.

Cite this