Nanocrystalline CeO2-δ coated β-MnO2 nanorods with enhanced oxygen transfer property
Abstract
In this research, β-MnO2 nanorods were synthesized by a hydrothermal method, followed by a facile precipitation method to obtain nanocrystalline CeO2-δ coated β-MnO2 nanorods. The as-prepared samples were characterized by XRD, HRTEM, FESEM, XPS and in-situ high-temperature XRD. The HRTEM results show that well dispersed CeO2-δ nanocrystals sized about 5 nm were coated on the surface of β-MnO2 nanorods. The oxygen storage and transfer property of as-synthesized materials were evaluated using TGA under various atmospheres (air, pure N2, and 5%H2/95%Ar). The TGA results indicate that CeO2-δ modification could favour the reduction of Mn4+ to Mn3+ and/or Mn2+ at lower temperature as compared with pure β-MnO2 nanorods and the physically mixed CeO2-δ-β-MnO2 under low oxygen partial pressure conditions (i.e., pure N2, 5%H2/95%Ar). Specifically, CeO2-δ@β-MnO2 sample can exhibit 7.5 wt% weight loss between 100 and 400 °C under flowing N2 and 11.4 wt% weight loss between 100 and 350 °C under flowing 5%H2/95%Ar. During the reduction process under pure N2 or 5%H2/95%Ar condition, the oxygen ions in β-MnO2 nanorods are expected to be released to the surroundings in the form of O2 or H2O with the coated CeO2-δ nanocrystals acting as mediator as inferred from the synergistic effect between the well-interacted CeO2-δ nanocrystals and β-MnO2 nanorods.
Citation
Huang , X , Zhao , G , Chang , Y , Wang , G & Irvine , J T S 2018 , ' Nanocrystalline CeO 2-δ coated β-MnO 2 nanorods with enhanced oxygen transfer property ' , Applied Surface Science , vol. 440 , pp. 20-28 . https://doi.org/10.1016/j.apsusc.2017.12.197
Publication
Applied Surface Science
Status
Peer reviewed
ISSN
0169-4332Type
Journal article
Rights
© 2017 Elsevier B. V. This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1016/j.apsusc.2017.12.197
Description
Prof. Ge Wang and Dr. Xiubing Huang acknowledged financial support from the National Key Research and Development Program of China (Grant No. 2016YFB0601100), and Fundamental Research Funds for the Central Universities (FRF-TP-16-028A1). Prof. John T. S. Irvine acknowledged funding from the Engineering and Physical Research Council for research award EP/K036769/1 and Platform Grant EP/K015540/1, the Royal Society Wolfson Merit Award, WRM 2012/R2.Collections
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