Title: The stability of LaMnO3 surfaces
Subtitle: A hybrid exchange density functional theory study of an alkaline fuel cell catalyst
Authors: Ahmed, E. A.
Mallia, G.
Kramer, Denis 
Kucernak, A. R.
Harrison, N. M.
Language: en
Subject (DDC): DDC::500 Naturwissenschaften und Mathematik
Issue Date: 1-Aug-2013
Publisher: Royal Society of Chemistry
Document Type: Article
Journal / Series / Working Paper (HSU): Journal of materials chemistry A 
Volume: 1
Issue: 37
Page Start: 11152
Page End: 11162
Publisher Place: London [u.a.]
LaMnO3 is an inexpensive alternative to precious metals (e.g. platinum) as a catalyst for the oxygen reduction reaction in alkaline fuel cells. In fact, recent studies have shown that among a range of non-noble metal catalysts, LaMnO3 provides the highest catalytic activity. Despite this, very little is known about LaMnO3 in the alkaline fuel cells environment, where the orthorhombic structure is most stable. In order to understand the reactivity of orthorhombic LaMnO3 we must first understand the surface structure. Hence, we have carried out calculations on its electrostatically stable low index surfaces using hybrid-exchange density functional theory, as implemented in CRYSTAL09. For each surface studied the calculated structure and formation energy is discussed. Among the surfaces studied the (100) surface was found to be the most stable with a formation energy of 0.98 J/m2. The surface energies are rationalised in terms of the cleavage of Jahn-Teller distorted Mn-O bonds, the compensation of undercoordination for ions in the terminating layer and relaxation effects. Finally, the equilibrium morphology of orthorhombic LaMnO3 crystals is predicted, allowing us to speculate about likely surface reaction sites.
Organization Units (connected with the publication): Department of Chemistry, Imperial College London
ISSN: 2050-7488
DOI: 10.1039/C3TA11382E
Appears in Collections:Publications of the HSU Researchers (before HSU)

Show full item record

CORE Recommender


checked on May 18, 2022

Google ScholarTM




Items in openHSU are protected by copyright, with all rights reserved, unless otherwise indicated.