The interaction of molecular oxygen on LaO terminated surfaces of La2NiO4
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Rare-earth metal oxides with perovskite-type crystal structures are under consideration for use as air electrode materials for intermediate to high temperature electrochemical device applications. The surface chemistry of these materials plays a critical role in determining the kinetics of oxygen reduction and exchange reactions. Among various perovskite-structured oxides, certain members of the Ruddlesden–Popper series, e.g. La2NiO4, have been identified as significantly active for surface oxygen interactions. However, the challenge remains to be the identification of the structure and composition of active surfaces, as well as the influence of these factors on the mechanisms of surface exchange reactions. In this contribution, the changes in the electronic structure and the energetics of oxygen interactions on the surfaces of La2NiO4 are analysed using first principles calculations in the Density Functional Theory (DFT) formalism. As for the surface chemistry, LaO termination rather than NiO2 termination is presumed due to recent experimental evidence of the surfaces of various perovskite structured oxides after heat treatment in oxidizing environments being transition metal free. Our findings substantiate the fact that the LaO-terminated surface can indeed participate in the formation of surface superoxo species. Detailed charge transfer analyses revealed that it is possible for such a surface to be catalytically active owing to the enhanced electronic configurations on the neighbouring La sites to surface species. In addition, positively charged oxygen vacancies, relative to the crystal lattice, can act as active sites and catalyse the O–O bond cleavage.
Date Issued
2016-09-14
Date Acceptance
2016-06-07
Citation
Journal of Materials Chemistry A, 2016, 4 (34), pp.13113-13124
ISSN
2050-7496
Publisher
Royal Society of Chemistry
Start Page
13113
End Page
13124
Journal / Book Title
Journal of Materials Chemistry A
Volume
4
Issue
34
Copyright Statement
This journal is © The Royal Society of Chemistry 2016
Subjects
Science & Technology
Physical Sciences
Technology
Chemistry, Physical
Energy & Fuels
Materials Science, Multidisciplinary
Chemistry
Materials Science
ENERGY ION-SCATTERING
ELASTIC BAND METHOD
WAVE BASIS-SET
TRANSPORT-PROPERTIES
SINGLE-CRYSTALS
DOPED LA2NIO4
SADDLE-POINTS
THIN-FILMS
OXIDE
DIFFUSION
Publication Status
Published
Date Publish Online
2016-06-23