Jump to main content
Jump to site search

Issue 48, 2018
Previous Article Next Article

Interplay between H2O and CO2 coadsorption and space-charge on Y-doped BaZrO3 surfaces

Author affiliations

Abstract

The present work quantifies the equilibrium defect and adsorbate chemistry on oxide surfaces in the presence of multiple gas components at elevated temperatures and sub-surface space charge. The concentrations of chemisorbed H2O and CO2 as well as surface protons and oxygen vacancies were calculated for Y-doped BaZrO3 using a thermodynamic framework with input from first-principles calculations. The overall energy of the system was minimized based on contributions from gas adsorption, interactions between defects and adsorbates, segregation of point defects and space-charge formation, as well as configurational entropy. The coverage dependent adsorption energies were found as −1.44 + 0.34ΘH2O eV and −2.25 + 1.21ΘCO2 eV for chemisorption of H2O and CO2, respectively. The interaction between the adsorbates was found to follow 1.72ΘH2OΘCO2 eV. The coverage of surface protons was above 0.3 up to 1000 K under most considered conditions (0.01–1 bar H2O, 4 × 10−4–1 bar CO2) due to a favorable interaction with both surface hydroxide and CO2 adsorbates. Most importantly, the results show that the coadsorption, adsorbate interactions or space-charge formation each played a major role in the obtained defect concentrations and surface coverages. Thus, the approach in this work demonstrates the importance of considering quantitatively each of these aspects in obtaining accurately the surface equilibria on complex catalytic oxides.

Graphical abstract: Interplay between H2O and CO2 coadsorption and space-charge on Y-doped BaZrO3 surfaces

Back to tab navigation

Supplementary files

Publication details

The article was received on 01 Oct 2018, accepted on 16 Nov 2018 and first published on 19 Nov 2018


Article type: Paper
DOI: 10.1039/C8TA09491H
Citation: J. Mater. Chem. A, 2018,6, 24823-24830
  • Open access: Creative Commons BY license
  •   Request permissions

    Interplay between H2O and CO2 coadsorption and space-charge on Y-doped BaZrO3 surfaces

    J. M. Polfus, J. Yang and B. Yildiz, J. Mater. Chem. A, 2018, 6, 24823
    DOI: 10.1039/C8TA09491H

    This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements