title: Water electrolysis on La(1-x)Sr(x)CoO(3-δ) perovskite electrocatalysts.
abstract: Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B-O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co-O bond and the concentration of oxygen vacancies are controlled through Sr(2+) substitution into La(1-x)Sr(x)CoO(3-δ) . We attempt to rationalize the high activities of La(1-x)Sr(x)CoO(3-δ) through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.
authors.affiliation: Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: J Tyler
authors.initials: JT
authors.lastname: Mefford
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Xi
authors.initials: X
authors.lastname: Rong
authors.affiliation: Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology, 143026 Moscow, Russia.|Electron Microscopy for Material Science, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
authors.forename: Artem M
authors.initials: AM
authors.lastname: Abakumov
authors.affiliation: Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: William G
authors.initials: WG
authors.lastname: Hardin
authors.affiliation: Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
authors.forename: Sheng
authors.initials: S
authors.lastname: Dai
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Alexie M
authors.initials: AM
authors.lastname: Kolpak
authors.affiliation: Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, USA.|Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Keith P
authors.initials: KP
authors.lastname: Johnston
authors.affiliation: Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, USA.|Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology, 143026 Moscow, Russia.|Texas Materials Institute, The University of Texas at Austin, Austin, Texas 78712, USA.|Center for Nano and Molecular Science and Technology, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Stevenson