skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

This content will become publicly available on November 27, 2019

Title: Ab Initio Thermodynamics of Iridium Surface Oxidation and Oxygen Evolution Reaction

Abstract

Iridium-based materials are considered as state-of-the-art electrocatalysts for oxygen evolution reaction (OER), however, their stability and catalytic activity greatly depend on surface-state changes induced by electrochemical cycling. To better understand the behavior of the low-index Ir surfaces in an electrochemical environment, we perform a systematic thermodynamic analysis by means of the density functional theory (DFT) calculations. On the basis of computed surface energies of the Ir (111), (110) and (100) facets as a function of applied electrode potential and coverage of adsorbed water species we determine stability maps and predict equilibrium shapes of Ir nanoparticles. Our calculations also show that metastable oxide precursors formed at the initial stages of Ir surface oxidation are responsible for enhanced catalytic activity toward OER as compared to metal surfaces covered by oxygen adsorbates and thick-oxide films. Such enhancement occurs not only due to the modified thermodynamic stability of OER intermediates, but also because thin-oxide layers may display the more energetically favorable I2M (interaction of two M–O units) rather than WNA (water nucleophilic attack) OER mechanism.

Authors:
ORCiD logo [1];  [1]; ORCiD logo [1]
  1. Univ. of Nebraska, Lincoln, NE (United States). Dept. of Chemical and Biomolecular Engineering
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC); Univ. of California, Oakland, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1543658
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 122; Journal Issue: 51; Journal ID: ISSN 1932-7447
Publisher:
American Chemical Society
Country of Publication:
United States
Language:
English
Subject:
Chemistry; Science & Technology - Other Topics; Materials Science

Citation Formats

Klyukin, Konstantin, Zagalskaya, Alexandra, and Alexandrov, Vitaly. Ab Initio Thermodynamics of Iridium Surface Oxidation and Oxygen Evolution Reaction. United States: N. p., 2018. Web. doi:10.1021/acs.jpcc.8b09868.
Klyukin, Konstantin, Zagalskaya, Alexandra, & Alexandrov, Vitaly. Ab Initio Thermodynamics of Iridium Surface Oxidation and Oxygen Evolution Reaction. United States. doi:10.1021/acs.jpcc.8b09868.
Klyukin, Konstantin, Zagalskaya, Alexandra, and Alexandrov, Vitaly. Tue . "Ab Initio Thermodynamics of Iridium Surface Oxidation and Oxygen Evolution Reaction". United States. doi:10.1021/acs.jpcc.8b09868.
@article{osti_1543658,
title = {Ab Initio Thermodynamics of Iridium Surface Oxidation and Oxygen Evolution Reaction},
author = {Klyukin, Konstantin and Zagalskaya, Alexandra and Alexandrov, Vitaly},
abstractNote = {Iridium-based materials are considered as state-of-the-art electrocatalysts for oxygen evolution reaction (OER), however, their stability and catalytic activity greatly depend on surface-state changes induced by electrochemical cycling. To better understand the behavior of the low-index Ir surfaces in an electrochemical environment, we perform a systematic thermodynamic analysis by means of the density functional theory (DFT) calculations. On the basis of computed surface energies of the Ir (111), (110) and (100) facets as a function of applied electrode potential and coverage of adsorbed water species we determine stability maps and predict equilibrium shapes of Ir nanoparticles. Our calculations also show that metastable oxide precursors formed at the initial stages of Ir surface oxidation are responsible for enhanced catalytic activity toward OER as compared to metal surfaces covered by oxygen adsorbates and thick-oxide films. Such enhancement occurs not only due to the modified thermodynamic stability of OER intermediates, but also because thin-oxide layers may display the more energetically favorable I2M (interaction of two M–O units) rather than WNA (water nucleophilic attack) OER mechanism.},
doi = {10.1021/acs.jpcc.8b09868},
journal = {Journal of Physical Chemistry. C},
number = 51,
volume = 122,
place = {United States},
year = {2018},
month = {11}
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on November 27, 2019
Publisher's Version of Record

Citation Metrics:
Cited by: 1 work
Citation information provided by
Web of Science

Save / Share: