Ceria-zirconia solid solutions (Ce1-xZrxO2-δ, x ≤ 0.2) for solar thermochemical water splitting: A thermodynamic study

Yong Hao, Chih Kai Yang, Sossina M. Haile*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

119 Scopus citations

Abstract

The redox behavior of ceria-zirconia solid solutions (or Zr-substituted ceria, ZSC) with a Zr content of up to 20 mol % is studied by thermogravimetry (TG) between 600 °C and 1490°C under controlled atmospheres. Thermodynamic properties, specifically standard oxidation enthalpy, ΔHoxdΘ, and entropy, ΔSoxdΘ, are derived from TG data. The raw TG results show that the extent of reduction is significantly increased (compared with undoped ceria), even at a low Zr substitution level of 5 mol %. Concomitantly, the magnitude of the thermodynamic functions dramatically decreases as a function of Zr content, particularly at low values of oxygen non-stoichiometry, θ (<3 mol %). Thermochemical fuel production from Zr-substituted ceria generally increases with increasing Zr content under both two-temperature and isothermal cycling conditions. In the case of two-temperature cycling, the benefit is accompanied by a penalty in the (computed) steam-to-hydrogen conversion ratio, whereas it is accompanied by a gain in this ratio for isothermal cycling. Overall, introduction of Zr has the potential to enhance solar-driven thermochemical fuel production, depending on the details of cycling conditions and reactor design.

Original languageEnglish (US)
Pages (from-to)6073-6082
Number of pages10
JournalChemistry of Materials
Volume26
Issue number20
DOIs
StatePublished - Oct 28 2014

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Ceria-zirconia solid solutions (Ce<sub>1-x</sub>Zr<sub>x</sub>O<sub>2-δ</sub>, x ≤ 0.2) for solar thermochemical water splitting: A thermodynamic study'. Together they form a unique fingerprint.

Cite this