Atomic‐Mesoscale Synergy in Amorphous Iridium Oxide Catalysts for Proton Exchange Membrane Water Electrolysis
Abstract
ABSTRACT Amorphous iridium oxide (IrO x ) is among the most active Ir‐based catalysts for the acidic oxygen evolution reaction (OER), yet its stability is severely limited because lattice‐oxygen participation often triggers irreversible oxygen loss that leads to iridium dissolution and structural degradation. Here, we present a surfactant‐directed synthesis of mesoporous IrO x electrocatalysts featuring a hollandite‐type local structure. This unique structure creates an atomic‐mesoscale synergy that enhances OER activity without sacrificing stability and improves high‐current‐density performance. At the atomic level, the hollandite‐type local structure promotes high OER activity and corrosion resistance. In situ spectroscopic and isotopic labeling experiments reveal a reversible cycle of lattice oxygen loss and reformation during OER. This process enables the flexible iridium local structure to transition between an initial six‐coordinate state and a low‐coordinated active state. At the mesoscale, an interconnected porous network ensures efficient mass transport and maximizes active‐site accessibility. As a result, this mesoporous electrocatalyst achieves a low cell voltage (1.75 V @ 2 A cm −2 ) and excellent stability for more than 2000 h (@ 2 A cm −2 ) in proton exchange membrane water electrolysis (PEMWE).
Article Details
Authors (12)
Hui Chen
Jiale Li
Ke Sun
Kun Qi
State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics
Xinyue Ni
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of Chemistry Jilin University Changchun China
Xiyang Wang
Department of Applied Physics
Haidong Xu
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, P. R. China
Muhan Na
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of Chemistry Jilin University Changchun China
Xiao Zhao
Zizhun Wang
Electron Microscopy Center Jilin University Changchun China
Yongcun Zou
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, P. R. China
Xiaoxin Zou
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry