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Lookup NU author(s): Dr Wei Chen, Dr Evangelos Papaioannou, Dr Brian Ray, Professor Ian Metcalfe
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2020When ceria is used as a support for many redox catalysis involved in green catalysis, it is well-known that the overlying noble metal can gain access to a significant quantity of oxygen atoms with high mobility and fast reduction and oxidation properties under mild conditions. However, it is as yet unclear what the underlying principle and the nature of the ceria surface involved are. By using two tailored morphologies of ceria nanocrystals, namely cubes and rods, it is demonstrated from Scanning Transmission Electron Microscopy with Electron Energy Loss Spectroscopy (STEM-EELS) mapping and Pulse Isotopic Exchange (PIE) that ceria nanocubes terminated with a polar surface (100) can give access to more than the top most layer of surface oxygen atoms. Also, they give higher oxygen mobility than ceria nanorods with a non-polar facet of (110). A new insight for the possible additional role of polar ceria surface plays in the oxygen mobility is obtained from Density Functional Theory (DFT) calculations which suggest that the (100) surface sites that has more than half-filled O on same plane can drive oxygen atoms to oxidise adsorbate(s) on Pd due to the strong electrostatic repulsion.
Author(s): Mahadi AH, Ye L, Fairclough SM, Qu J, Wu S, Chen W, Papaioannou EI, Ray B, Pennycook TJ, Haigh SJ, Young NP, Tedsree K, Metcalfe IS, Tsang SCE
Publication type: Article
Publication status: Published
Journal: Applied Catalysis B: Environmental
Year: 2020
Volume: 270
Print publication date: 05/08/2020
Online publication date: 04/03/2020
Acceptance date: 29/02/2020
Date deposited: 14/05/2020
ISSN (print): 0926-3373
Publisher: Elsevier B.V.
URL: https://doi.org/10.1016/j.apcatb.2020.118843
DOI: 10.1016/j.apcatb.2020.118843
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