Rutile (β-)MnO2 surfaces and vacancy formation for high electrochemical and catalytic performance

Research output: Contribution to journalArticle

  • 78 Citations

Abstract


MnO2 is a technologically important material for energy storage and catalysis. Recent investigations have demonstrated the success of nanostructuring for improving the performance of rutile MnO2 in Li-ion batteries and supercapacitors and as a catalyst. Motivated by this we have investigated the stability and electronic structure of rutile (β-)MnO2 surfaces using density functional theory. A Wulff construction from relaxed surface energies indicates a rod-like equilibrium morphology that is elongated along the c-axis, and is consistent with the large number of nanowire-type structures that are obtainable experimentally. The (110) surface dominates the crystallite surface area. Moreover, higher index surfaces than considered in previous work, for instance the (211) and (311) surfaces, are also expressed to cap the rod-like morphology. Broken coordinations at the surface result in enhanced magnetic moments at Mn sites that may play a role in catalytic activity. The calculated formation energies of oxygen vacancy defects and Mn reduction at key surfaces indicate facile formation at surfaces expressed in the equilibrium morphology. The formation energies are considerably lower than for comparable structures such as rutile TiO2 and are likely to be important to the high catalytic activity of rutile MnO2.

LanguageEnglish
Pages1418-1426
Number of pages9
JournalJournal of the American Chemical Society
Volume136
Issue number4
Early online date6 Jan 2014
DOIs
StatusPublished - 29 Jan 2014

Fingerprint

Vacancies
Nanowires
Catalysis
Catalyst activity
Ions
Oxygen
titanium dioxide
Oxygen vacancies
Magnetic moments
Interfacial energy
Energy storage
Electronic structure
Density functional theory
Defects
Catalysts

Cite this

Rutile (β-)MnO2 surfaces and vacancy formation for high electrochemical and catalytic performance. / Tompsett, David A.; Parker, Stephen C.; Islam, M. Saiful.

In: Journal of the American Chemical Society, Vol. 136, No. 4, 29.01.2014, p. 1418-1426.

Research output: Contribution to journalArticle

@article{b0674f6122ca44fba6de37c9eb08bc27,
title = "Rutile (β-)MnO2 surfaces and vacancy formation for high electrochemical and catalytic performance",
abstract = "MnO2 is a technologically important material for energy storage and catalysis. Recent investigations have demonstrated the success of nanostructuring for improving the performance of rutile MnO2 in Li-ion batteries and supercapacitors and as a catalyst. Motivated by this we have investigated the stability and electronic structure of rutile (β-)MnO2 surfaces using density functional theory. A Wulff construction from relaxed surface energies indicates a rod-like equilibrium morphology that is elongated along the c-axis, and is consistent with the large number of nanowire-type structures that are obtainable experimentally. The (110) surface dominates the crystallite surface area. Moreover, higher index surfaces than considered in previous work, for instance the (211) and (311) surfaces, are also expressed to cap the rod-like morphology. Broken coordinations at the surface result in enhanced magnetic moments at Mn sites that may play a role in catalytic activity. The calculated formation energies of oxygen vacancy defects and Mn reduction at key surfaces indicate facile formation at surfaces expressed in the equilibrium morphology. The formation energies are considerably lower than for comparable structures such as rutile TiO2 and are likely to be important to the high catalytic activity of rutile MnO2.",
author = "Tompsett, {David A.} and Parker, {Stephen C.} and Islam, {M. Saiful}",
year = "2014",
month = "1",
day = "29",
doi = "10.1021/ja4092962",
language = "English",
volume = "136",
pages = "1418--1426",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "AMER CHEMICAL SOC",
number = "4",

}

TY - JOUR

T1 - Rutile (β-)MnO2 surfaces and vacancy formation for high electrochemical and catalytic performance

AU - Tompsett,David A.

AU - Parker,Stephen C.

AU - Islam,M. Saiful

PY - 2014/1/29

Y1 - 2014/1/29

N2 - MnO2 is a technologically important material for energy storage and catalysis. Recent investigations have demonstrated the success of nanostructuring for improving the performance of rutile MnO2 in Li-ion batteries and supercapacitors and as a catalyst. Motivated by this we have investigated the stability and electronic structure of rutile (β-)MnO2 surfaces using density functional theory. A Wulff construction from relaxed surface energies indicates a rod-like equilibrium morphology that is elongated along the c-axis, and is consistent with the large number of nanowire-type structures that are obtainable experimentally. The (110) surface dominates the crystallite surface area. Moreover, higher index surfaces than considered in previous work, for instance the (211) and (311) surfaces, are also expressed to cap the rod-like morphology. Broken coordinations at the surface result in enhanced magnetic moments at Mn sites that may play a role in catalytic activity. The calculated formation energies of oxygen vacancy defects and Mn reduction at key surfaces indicate facile formation at surfaces expressed in the equilibrium morphology. The formation energies are considerably lower than for comparable structures such as rutile TiO2 and are likely to be important to the high catalytic activity of rutile MnO2.

AB - MnO2 is a technologically important material for energy storage and catalysis. Recent investigations have demonstrated the success of nanostructuring for improving the performance of rutile MnO2 in Li-ion batteries and supercapacitors and as a catalyst. Motivated by this we have investigated the stability and electronic structure of rutile (β-)MnO2 surfaces using density functional theory. A Wulff construction from relaxed surface energies indicates a rod-like equilibrium morphology that is elongated along the c-axis, and is consistent with the large number of nanowire-type structures that are obtainable experimentally. The (110) surface dominates the crystallite surface area. Moreover, higher index surfaces than considered in previous work, for instance the (211) and (311) surfaces, are also expressed to cap the rod-like morphology. Broken coordinations at the surface result in enhanced magnetic moments at Mn sites that may play a role in catalytic activity. The calculated formation energies of oxygen vacancy defects and Mn reduction at key surfaces indicate facile formation at surfaces expressed in the equilibrium morphology. The formation energies are considerably lower than for comparable structures such as rutile TiO2 and are likely to be important to the high catalytic activity of rutile MnO2.

UR - http://www.scopus.com/inward/record.url?scp=84893449444&partnerID=8YFLogxK

U2 - 10.1021/ja4092962

DO - 10.1021/ja4092962

M3 - Article

VL - 136

SP - 1418

EP - 1426

JO - Journal of the American Chemical Society

T2 - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 4

ER -