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Gettering La Effect from La 3 IrO 7 as a Highly Efficient Electrocatalyst for Oxygen Evolution Reaction in Acid Media
Author(s) -
Qin Qing,
Jang Haeseong,
Wang Yimeng,
Zhang Lijie,
Li Zijian,
Kim Min Gyu,
Liu Shangguo,
Liu Xien,
Cho Jaephil
Publication year - 2021
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.202003561
Subject(s) - electrocatalyst , overpotential , oxygen evolution , materials science , electrochemistry , water splitting , iridium , electrolysis of water , electrolysis , catalysis , inorganic chemistry , chemical engineering , electrode , chemistry , photocatalysis , biochemistry , engineering , electrolyte
Developing highly active, durable, and cost‐effective electrocatalysts for the oxygen evolution reaction (OER) is of prime importance in proton exchange membrane (PEM) water electrolysis techniques. Herein, a surface lanthanum‐deficient (SLD) iridium oxide as a highly efficient OER electrocatalyst is reported (labeled as La 3 IrO 7 ‐SLD), which is obtained by electrochemical activation, and shows better activity and durability than that of commerically available IrO 2 as well as most of the reported Ir‐based OER electrocatalysts. At a current density of 10 mA cm −2 , the overpotential of La 3 IrO 7 ‐SLD is 296 mV, which is lower than that of IrO 2 (316 mV). Impressively, the increase of potential is less than 50 mV at a voltage–time chronopotentiometry extending for 60 000 s using a glass carbon electrode that is vastly superior to IrO 2 . Moreover, the mass activity of the catalyst is approximately five times higher than that of IrO 2 at 1.60 V versus reversible hydrogen electrode. Density functional theory calculations suggest that a lattice oxygen participating mechanism with central Ir atoms serving as active sites (LOM‐Ir) rationalizes the high activity and durability for the La 3 IrO 7 ‐SLD electrocatalyst. The favorable energy level of surface active Ir 5d orbitals relative to coordinated O 2p orbitals makes the La 3 IrO 7 ‐SLD more active.