Details

Autor(en) / Beteiligte

• Hao, Yong
• Yang, Chih-Kai
• Haile, Sossina M

Titel

Ceria–Zirconia Solid Solutions (Ce1–x Zr x O2−δ, x ≤ 0.2) for Solar Thermochemical Water Splitting: A Thermodynamic Study

Ist Teil von

• Chemistry of materials, 2014-10, Vol.26 (20), p.6073-6082

Ort / Verlag

American Chemical Society

Erscheinungsjahr

2014

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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, ΔH oxd ⊖, and entropy, ΔS oxd ⊖, 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, δ (<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.