ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
PdCeO2-Loading effect-20210326.pdf (2.86 MB)

Are All Single Atoms Created Equal? Surface Density Dependent Catalytic Activity of Single Pd Atoms Supported on Ceria

preprint
submitted on 26.03.2021, 01:05 and posted on 26.03.2021, 12:10 by Yongseon Kim, Gregory Collinge, Mal Soon Lee, Konstantin Khivantsev, Sung June Cho, Vassiliki-Alexandra Glezakou, Roger Rousseau, Janos Szanyi, Ja Hun Kwak
The analogy between single atom catalysts (SACs) and molecular catalysts predicts that the specific catalytic activity of these systems is constant. We provide evidence that this prediction is not necessarily true. As a case in point, we show that the specific activity over ceria5 supported single Pd atoms linearly increases with metal atom density, originating from the cumulative enhancement of lattice oxygen mobility. The long-range electrostatic fingerprints (~1.5 nm) around each Pd site overlap with each other as surface Pd density increases, resulting in the observed deviation from constant specific activity. These cooperative effects exhaust previously active O atoms above a certain Pd density, leading to their permanent 10 removal and consequent drop in reaction rate. The findings of our combined experimental and computational study show that the specific catalytic activity of reducible oxide-supported single atom catalysts can be tuned by varying the surface density of single metal atoms.

Funding

National Science Foundation(No. 10 2016R1A5A1009405, 2017R1A2B4007310)

History

Email Address of Submitting Author

jhkwak@unist.ac.kr

Institution

Ulsan National Institute of Science and Technology

Country

Korea

ORCID For Submitting Author

0000-0001-5245-0765

Declaration of Conflict of Interest

No conflict of interest

Version Notes

Version 1.0

Exports

ChemRxiv

Exports