On the structural stability of crystalline ceria phases in undoped and acceptor-doped ceria materials under in situ reduction conditions.

ABSTRACT: The reduction of pure and Sm-doped ceria in hydrogen has been studied by synchrotron-based in situ X-ray diffraction to eventually prove or disprove the presence of crystalline cerium hydride (CeH _x ) phases and the succession of potential structural phase (trans)formations of reduced cerium oxide phases during heating-cooling cycles up to 1273 K. Despite a recent report on the existence of bulk and surface CeH _x phases during reductive treatment of pure CeO₂ in H₂, structural analysis by Rietveld refinement as well as additional ¹H-NMR spectroscopy did not reveal the presence of any crystalline CeH _x phase. Rather, a sequence of phase transformations during the re-cooling process in H₂

SUBMITTER: Bekheet MF 

PROVIDER: S-EPMC6394889 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature