Interaction of Hydrogen with Ceria: Hydroxylation, Reduction, and Hydride Formation on the Surface and in the Bulk.

ABSTRACT: The study reports the first attempt to address the interplay between surface and bulk in hydride formation in ceria (CeO₂ ) by combining experiment, using surface sensitive and bulk sensitive spectroscopic techniques on the two sample systems, i.e., CeO₂ (111) thin films and CeO₂ powders, and theoretical calculations of CeO₂ (111) surfaces with oxygen vacancies (O_v ) at the surface and in the bulk. We show that, on a stoichiometric CeO₂ (111) surface, H₂ dissociates and forms surface hydroxyls (OH). On the pre-reduced CeO_2-x samples, both films and powders, hydroxyls and hydrides (Ce-H) are formed on the surface as well as in the bulk, accompanied by the Ce³⁺ ↔ Ce⁴⁺ redox reaction.

SUBMITTER: Li Z 

PROVIDER: S-EPMC8048454 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature