Doping
CeO2 with Pd atoms has been associated with catalytic
CO oxidation, but current surface models do not allow CO adsorption.
Here, we report a new structure of Pd-doped CeO2(111),
in which Pd adopts a square planar configuration instead of the previously
assumed octahedral configuration. Oxygen removal from this doped structure
is favorable. The resulting defective Pd-doped CeO2 surface
is active for CO oxidation and is also able to cleave the first C–H
bond in methane. We show how the moderate CO adsorption energy and
dynamic features of the Pd atom upon CO adsorption and CO oxidation
contribute to a low-barrier catalytic cycle for CO oxidation. These
structures, which are also observed for Ni and Pt, can lead to a more
open coordination environment around the doped-transition-metal center.
These thermally stable structures are relevant to the development
of single-atom catalysts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.