Articles
  • Synthesis of Ce2O3 and characterization of hydrogen insertion using neutron diffraction and spectroscopic methods

  • Ki-Woong Chaea, Ta-Ryeong Parkb and Jeong Seog Kima,*

  • aDept. of Materials Science and Engineering, Hoseo University, Asan, Chungnam 31499, Korea
    bDept. of Display Engineering, Hoseo University, Asan, Chungnam 31499, Korea

  • This article is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The catalytic activity of ceria originates from oxygen vacancies. Ce2O3 is the most oxygen-deficient end-member of non-stoichiometric ceria, CeO2-x. A new method of synthesizing air-stable Ce2O3 from the micron- and nano-sized CeO2 powder was developed. The key part of this synthetic process is to reduce the sample in a low-pressure H2 gas (10 Torr) under vacuum at 1300°C. The percentage of the Ce2O3 phase in the reduced sample ranges from 55% ~ 96 wt.% according to the powder size and reduction time. Hydrogen incorporation in reduced ceria was confirmed by secondary ion mass spectrometry depth profile analysis and vibrational spectroscopic techniques, such as Raman and Fourier transform infrared spectroscopy. The surface region (zero depth) showed the highest H concentration that decreased with increasing profiling depth. The locations of hydrogen incorporated in the Ce2O3 phase in the reduced sample were revealed by calculating the nuclear density distribution. The maximum entropy method-based pattern fitting and Dysnomia program were combined to calculate the nuclear density map using the neutron diffraction data


Keywords: ceria, hydrogen insertion, structural analysis, nuclear density distribution, spectroscopy

This Article

  • 2021; 22(4): 461-469

    Published on Aug 31, 2021

  • 10.36410/jcpr.2021.22.4.461
  • Received on Feb 1, 2021
  • Revised on Apr 6, 2021
  • Accepted on Apr 19, 2021

Correspondence to

  • Jeong Seog Kim

  • Dept. of Materials Science and Engineering, Hoseo University, Asan, Chungnam 31499, Korea
    Tel : +82-10-4058-8085 Fax: +82-41-360-4849

  • E-mail: kimjungs@hoseo.edu