Thermal stability and surface behaviors of CeO2/Si films during in-situ vacuum annealing

Gas–solid interaction of H2–Ce0.95Zr0.05O2: new insights into surface participation in heterogeneous catalysis

“…Skorodumova et al 23 showed a quantum mechanical picture of the mechanism of CeO 2 to Ce 2 O 3 and suggested that the redox transformation involves the oxygen vacancy migration as well as the delocalization of an electron on a Ce atom. On the other hand, Luo and co-workers 24 studied the thermal stability of ceria and found that the complete reduction of ceria is not possible even after vacuum annealing at 1000 K. To correlate the redox nature of ceria with realistic conditions, many efforts have been made to the oxygen vacancy generation ability and its migration with different gaseous environments like CO 2 , 25 O 2 , CO, NO x and H 2 . 26 Sohlberg et al 27 used combined first-principles calculation and thermodynamic arguments and concluded that there is a spontaneous uptake of H 2 at a temperature of around 665 K on ceria, and the hydrogen forms an -OH group in the bulk, whereas Chafi et al 28 predicted that the hydrogen uptake results in the formation of bulk as well as surface OH groups.…”

In Situ Study of Particle Precipitation in Metal-Doped CeO2 during Thermal Treatment and Ion Irradiation for Emulation of Irradiating Fuels

“…Ceria is known to have an excellent capability for oxygen storage and release. , Charged oxygen vacancies are created in the reduction process to stabilize the cubic ceria crystal structure. A previous report indicates that the reduction occurred at 700 K during vacuum annealing of CeO 2 , and a complete reduction of Ce from 4+ to 3+ was not achieved at 1000 K for 1 h. Presence of the O vacancies in the crystal structure could assist metallic dopants to diffuse and precipitate at elevated temperatures (1073 K). Under ion irradiation at 673 K, Pd diffusion was enhanced and small Pd precipitates was observed in CeO x matrix .…”