Abstract
Redox cycles utilize the reversible oxygen release/uptake of cerium oxide in a variety of renewable energy applications such as fuel cells, water gas shift reactions, and solar thermochemical fuel production. For all applications the degree of reduction/oxidation determines the overall performance. In this study we report on the redox behavior of MxCe1–xO2−δ (M = Zr, Hf; x = 0, 0.15, 0.2) solid solutions monitored by high-temperature in situ X-ray diffraction. During reduction in H2 at 600 °C and the successive formation of Ce3+ and oxygen vacancies, the lattice of ceria expands up to 0.3%. The lattice expansion of hafnium-doped ceria samples is 4 times larger than in zirconium-doped or undoped ceria, indicating drastically higher extents of oxygen vacancy formation. The same trends are validated using temperature-programmed reduction measurements. Complete reoxidation of the MxCe1–xO2−δ solid solutions in air at 600 °C is reflecting the reversibility of the redox process. Scanning electron microscopy and...
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
