Open AccessDynamically Stable Active Sites from Surface Evolution of Perovskite Materials during the Oxygen Evolution Reaction
Author(s) -
Pietro Papa Lopes,
Dong Young Chung,
Rui Xue,
Hong Zheng,
Haiying He,
Pedro Farinazzo Bergamo Dias Martins,
Dušan Strmčnik,
Vojislav R. Stamenković,
Peter Zapol,
J. F. Mitchell,
Robert F. Klie,
Nenad M. Marković
Publication year - 2021
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.0c08959
Subject(s) - oxygen evolution , chemistry , dissolution , perovskite (structure) , oxide , catalysis , electrolyte , oxygen , chemical engineering , inorganic chemistry , divalent , active site , electrode , crystallography , organic chemistry , electrochemistry , engineering
Perovskite oxides are an important class of oxygen evolution reaction (OER) catalysts in alkaline media, despite the elusive nature of their active sites. Here, we demonstrate that the origin of the OER activity in a La 1- x Sr x CoO 3 model perovskite arises from a thin surface layer of Co hydr(oxy)oxide (CoO x H y ) that interacts with trace-level Fe species present in the electrolyte, creating dynamically stable active sites. Generation of the hydr(oxy)oxide layer is a consequence of a surface evolution process driven by the A-site dissolution and O-vacancy creation. In turn, this imparts a 10-fold improvement in stability against Co dissolution and a 3-fold increase in the activity-stability factor for CoO x H y /LSCO when compared to nanoscale Co-hydr(oxy)oxides clusters. Our results suggest new design rules for active and stable perovskite oxide-based OER materials.
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