The University of Southampton
University of Southampton Institutional Repository

Optimizing oxygen reduction catalyst morphologies from first principles

Optimizing oxygen reduction catalyst morphologies from first principles
Optimizing oxygen reduction catalyst morphologies from first principles
Catalytic activity of perovskites for oxygen reduction (ORR) was recently correlated with bulk d-electron occupancy of the transition metal. We expand on the resultant model, which successfully reproduces the high activity of LaMnO3 relative to other perovskites, by addressing catalyst surface morphology as an important aspect of the optimal ORR catalyst. The nature of reaction sites on low index surfaces of orthorhombic (Pnma) LaMnO3 is established from First Principles. The adsorption of O2 is markedly influenced by local geometry and strong electron correlation. Only one of the six reactions sites that result from experimentally confirmed symmetry-breaking Jahn?Teller distortions is found to bind O2 with an intermediate binding energy while facilitating the formation of superoxide, an important ORR intermediate in alkaline media. As demonstrated here for LaMnO3, rational design of the catalyst morphology to promote specific active sites is a highly effective optimization strategy for advanced functional ORR catalysts
1932-7447
16804-16810
Ahmad, Ehsan A.
08eda7b9-8162-4a07-8809-9da70dd41d91
Tileli, Vasiliki
7c65a31e-964b-4e1b-ac3d-e131e1fb04ce
Kramer, Denis
1faae37a-fab7-4edd-99ee-ae4c30d3cde4
Mallia, Giuseppe
368e2f86-d65e-4905-88c3-150a69aca618
Stoerzinger, Kelsey A.
e147c027-7444-4633-85c3-2b2e50ed1669
Shao-Horn, Yang
e55d99c2-6bde-4a3d-8542-48406bd0effa
Kucernak, Anthony R.
3a0f1914-9ef6-40dc-87df-38aba7e4ceaf
Harrison, Nicholas M.
0a3ae276-b50e-492e-9245-a6c9985d7616
Ahmad, Ehsan A.
08eda7b9-8162-4a07-8809-9da70dd41d91
Tileli, Vasiliki
7c65a31e-964b-4e1b-ac3d-e131e1fb04ce
Kramer, Denis
1faae37a-fab7-4edd-99ee-ae4c30d3cde4
Mallia, Giuseppe
368e2f86-d65e-4905-88c3-150a69aca618
Stoerzinger, Kelsey A.
e147c027-7444-4633-85c3-2b2e50ed1669
Shao-Horn, Yang
e55d99c2-6bde-4a3d-8542-48406bd0effa
Kucernak, Anthony R.
3a0f1914-9ef6-40dc-87df-38aba7e4ceaf
Harrison, Nicholas M.
0a3ae276-b50e-492e-9245-a6c9985d7616

Ahmad, Ehsan A., Tileli, Vasiliki, Kramer, Denis, Mallia, Giuseppe, Stoerzinger, Kelsey A., Shao-Horn, Yang, Kucernak, Anthony R. and Harrison, Nicholas M. (2015) Optimizing oxygen reduction catalyst morphologies from first principles. The Journal of Physical Chemistry C, 119 (29), 16804-16810. (doi:10.1021/acs.jpcc.5b05460).

Record type: Article

Abstract

Catalytic activity of perovskites for oxygen reduction (ORR) was recently correlated with bulk d-electron occupancy of the transition metal. We expand on the resultant model, which successfully reproduces the high activity of LaMnO3 relative to other perovskites, by addressing catalyst surface morphology as an important aspect of the optimal ORR catalyst. The nature of reaction sites on low index surfaces of orthorhombic (Pnma) LaMnO3 is established from First Principles. The adsorption of O2 is markedly influenced by local geometry and strong electron correlation. Only one of the six reactions sites that result from experimentally confirmed symmetry-breaking Jahn?Teller distortions is found to bind O2 with an intermediate binding energy while facilitating the formation of superoxide, an important ORR intermediate in alkaline media. As demonstrated here for LaMnO3, rational design of the catalyst morphology to promote specific active sites is a highly effective optimization strategy for advanced functional ORR catalysts

Text
acs%2Ejpcc%2E5b05460.pdf - Accepted Manuscript
Download (4MB)

More information

Submitted date: 8 June 2015
e-pub ahead of print date: 15 July 2015
Organisations: Engineering Mats & Surface Engineerg Gp

Identifiers

Local EPrints ID: 379208
URI: http://eprints.soton.ac.uk/id/eprint/379208
ISSN: 1932-7447
PURE UUID: bdfdde1e-fb4f-4c12-8350-cfc17f85e168

Catalogue record

Date deposited: 24 Jul 2015 10:30
Last modified: 04 Nov 2019 20:13

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×