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Title: Electrochemical trapping of metastable Mn 3+ ions for activation of MnO 2 oxygen evolution catalysts

Electrodeposited manganese oxide films are promising catalysts for promoting the oxygen evolution reaction (OER), especially in acidic solutions. The activity of these catalysts is known to be enhanced by the introduction of Mn 3+. We present in situ electrochemical and X-ray absorption spectroscopic studies, which reveal that Mn 3+ may be introduced into MnO 2 by an electrochemically induced comproportionation reaction with Mn 2+ and that Mn 3+ persists in OER active films. Extended X-ray absorption fine structure (EXAFS) spectra of the Mn 3+-activated films indicate a decrease in the Mn–O coordination number, and Raman microspectroscopy reveals the presence of distorted Mn–O environments. Computational studies show that Mn 3+ is kinetically trapped in tetrahedral sites and in a fully oxidized structure, consistent with the reduction of coordination number observed in EXAFS. Although in a reduced state, computation shows that Mn 3+ states are stabilized relative to those of oxygen and that the highest occupied molecular orbital (HOMO) is thus dominated by oxygen states. Furthermore, the Mn 3+(T d) induces local strain on the oxide sublattice as observed in Raman spectra and results in a reduced gap between the HOMO and the lowest unoccupied molecular orbital (LUMO). As a result, themore » confluence of a reduced HOMO–LUMO gap and oxygen-based HOMO results in the facilitation of OER on the application of anodic potentials to the δ-MnO 2 polymorph incorporating Mn 3+ ions.« less
Authors:
 [1] ;  [2] ;  [3] ;  [1] ;  [4] ;  [5] ;  [6] ;  [3] ; ORCiD logo [1]
  1. Harvard Univ., Cambridge, MA (United States)
  2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  3. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  4. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Menlo Park, CA (United States)
  5. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States)
  6. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Grant/Contract Number:
AC36-08GO28308; AC02-76SF00515; 1541959
Type:
Published Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 115; Journal Issue: 23; Journal ID: ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; manganese oxide; polymorph; water splitting; catalysis; renewable energy storage
OSTI Identifier:
1438083
Alternate Identifier(s):
OSTI ID: 1458415

Chan, Zamyla Morgan, Kitchaev, Daniil A., Weker, Johanna Nelson, Schnedermann, Christoph, Lim, Kipil, Ceder, Gerbrand, Tumas, William, Toney, Michael F., and Nocera, Daniel G.. Electrochemical trapping of metastable Mn3+ ions for activation of MnO2 oxygen evolution catalysts. United States: N. p., Web. doi:10.1073/pnas.1722235115.
Chan, Zamyla Morgan, Kitchaev, Daniil A., Weker, Johanna Nelson, Schnedermann, Christoph, Lim, Kipil, Ceder, Gerbrand, Tumas, William, Toney, Michael F., & Nocera, Daniel G.. Electrochemical trapping of metastable Mn3+ ions for activation of MnO2 oxygen evolution catalysts. United States. doi:10.1073/pnas.1722235115.
Chan, Zamyla Morgan, Kitchaev, Daniil A., Weker, Johanna Nelson, Schnedermann, Christoph, Lim, Kipil, Ceder, Gerbrand, Tumas, William, Toney, Michael F., and Nocera, Daniel G.. 2018. "Electrochemical trapping of metastable Mn3+ ions for activation of MnO2 oxygen evolution catalysts". United States. doi:10.1073/pnas.1722235115.
@article{osti_1438083,
title = {Electrochemical trapping of metastable Mn3+ ions for activation of MnO2 oxygen evolution catalysts},
author = {Chan, Zamyla Morgan and Kitchaev, Daniil A. and Weker, Johanna Nelson and Schnedermann, Christoph and Lim, Kipil and Ceder, Gerbrand and Tumas, William and Toney, Michael F. and Nocera, Daniel G.},
abstractNote = {Electrodeposited manganese oxide films are promising catalysts for promoting the oxygen evolution reaction (OER), especially in acidic solutions. The activity of these catalysts is known to be enhanced by the introduction of Mn3+. We present in situ electrochemical and X-ray absorption spectroscopic studies, which reveal that Mn3+ may be introduced into MnO2 by an electrochemically induced comproportionation reaction with Mn2+ and that Mn3+ persists in OER active films. Extended X-ray absorption fine structure (EXAFS) spectra of the Mn3+-activated films indicate a decrease in the Mn–O coordination number, and Raman microspectroscopy reveals the presence of distorted Mn–O environments. Computational studies show that Mn3+ is kinetically trapped in tetrahedral sites and in a fully oxidized structure, consistent with the reduction of coordination number observed in EXAFS. Although in a reduced state, computation shows that Mn3+ states are stabilized relative to those of oxygen and that the highest occupied molecular orbital (HOMO) is thus dominated by oxygen states. Furthermore, the Mn3+(Td) induces local strain on the oxide sublattice as observed in Raman spectra and results in a reduced gap between the HOMO and the lowest unoccupied molecular orbital (LUMO). As a result, the confluence of a reduced HOMO–LUMO gap and oxygen-based HOMO results in the facilitation of OER on the application of anodic potentials to the δ-MnO2 polymorph incorporating Mn3+ ions.},
doi = {10.1073/pnas.1722235115},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 23,
volume = 115,
place = {United States},
year = {2018},
month = {5}
}

Works referenced in this record:

Generalized Gradient Approximation Made Simple
journal, October 1996
  • Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
  • Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
  • DOI: 10.1103/PhysRevLett.77.3865

Powering the planet: Chemical challenges in solar energy utilization
journal, October 2006
  • Lewis, N. S.; Nocera, D. G.
  • Proceedings of the National Academy of Sciences, Vol. 103, Issue 43, p. 15729-15735
  • DOI: 10.1073/pnas.0603395103

From ultrasoft pseudopotentials to the projector augmented-wave method
journal, January 1999

Electron correlation in semiconductors and insulators: Band gaps and quasiparticle energies
journal, October 1986

In Situ Formation of an Oxygen-Evolving Catalyst in Neutral Water Containing Phosphate and Co2+
journal, August 2008

Opportunities and challenges for a sustainable energy future
journal, August 2012
  • Chu, Steven; Majumdar, Arun
  • Nature, Vol. 488, Issue 7411, p. 294-303
  • DOI: 10.1038/nature11475

Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set
journal, July 1996