Substrate‐Driven Catalyst Reducibility for Oxygen Evolution and Its Effect on the Operation of Proton Exchange Membrane Water Electrolyzers

To increase the efficiency of hydrogen production by proton exchange membrane water electrolyzers (PEMWEs), the relationships between the specific activity and stability of the membrane–electrode assembly (MEA) must be clarified. Ir oxide electrodeposited on Ti substrate is used as an oxygen electrode, and its electronic properties and electrochemical behavior in PEMWE operation are observed. The electrode, fabricated through a facile strategy based on annealing in the air atmosphere, enhances the specific oxygen evolution reaction (OER) activity and stability in PEMWE operation. Furthermore, the electronic catalyst–substrate interactions associated with different reducibilities in the heteroatom system are studied. The morphology, electronic properties, and chemical state of the oxygen electrode are investigated through X‐ray spectroscopy, microscopy techniques, and computational analyses. Thermal treatment of the catalyst‐coated substrate decreases the bulk oxidation state of Ir and increases the surface oxidation state. According to the electrochemical and physical behavior analyses of PEMWEs, the oxygen content in the Ir oxide structure, which defines the OER activity and its stability, is influenced by the crystalline structure and formation of a stable interface between the catalyst and substrate. The outcomes can facilitate the development of strategies for enhancing the performance of PEMWEs and designing rational MEAs.

[1]  B. Xia,et al.  Key Components and Design Strategy for a Proton Exchange Membrane Water Electrolyzer , 2022, Small Structures.

[2]  Xiaoming Sun,et al.  Iridium Doped Pyrochlore Ruthenates for Efficient and Durable Electrocatalytic Oxygen Evolution in Acidic Media. , 2022, Small.

[3]  D. Bessarabov,et al.  Supported Ir-Based Oxygen Evolution Catalysts for Polymer Electrolyte Membrane Water Electrolysis: A Minireview , 2022, Energy & Fuels.

[4]  K. Ayers,et al.  Exploring the Impacts of Conditioning on Proton Exchange Membrane Electrolyzers by In Situ Visualization and Electrochemistry Characterization. , 2022, ACS applied materials & interfaces.

[5]  R. Hanke-Rauschenbach,et al.  Is iridium demand a potential bottleneck in the realization of large-scale PEM water electrolysis? , 2021, International Journal of Hydrogen Energy.

[6]  K. Bhattacharyya,et al.  Structure and Reactivity of IrOx Nanoparticles for the Oxygen Evolution Reaction in Electrocatalysis: An Electronic Structure Theory Study , 2021 .

[7]  U. Krewer,et al.  Identifying the oxygen evolution mechanism by microkinetic modelling of cyclic voltammograms , 2021, Electrochimica Acta.

[8]  A. Jäger-Waldau,et al.  Green hydrogen in Europe – A regional assessment: Substituting existing production with electrolysis powered by renewables , 2020 .

[9]  Zhichuan J. Xu,et al.  Covalency competition dominates the water oxidation structure–activity relationship on spinel oxides , 2020, Nature Catalysis.

[10]  Bote Zhao,et al.  Densely Populated Single Atom Catalysts , 2020 .

[11]  S. Noda,et al.  Amorphous Catalysts and Electrochemical Water Splitting: An Untold Story of Harmony. , 2019, Small.

[12]  Benjamin Paul,et al.  Tailored mesoporous Ir/TiOx: Identification of structure-activity relationships for an efficient oxygen evolution reaction , 2019, Journal of Catalysis.

[13]  Gengfeng Zheng,et al.  Doping strain induced bi-Ti3+ pairs for efficient N2 activation and electrocatalytic fixation , 2019, Nature Communications.

[14]  P. Strasser,et al.  Experimental Activity Descriptors for Iridium-Based Catalysts for the Electrochemical Oxygen Evolution Reaction (OER) , 2019, ACS Catalysis.

[15]  Dong Woog Lee,et al.  Ultra-low loading of IrO2 with an inverse-opal structure in a polymer-exchange membrane water electrolysis , 2019, Nano Energy.

[16]  Wensheng Yan,et al.  Activating Inert, Nonprecious Perovskites with Iridium Dopants for Efficient Oxygen Evolution Reaction under Acidic Conditions. , 2019, Angewandte Chemie.

[17]  K. Ayers,et al.  Nano-size IrOx catalyst of high activity and stability in PEM water electrolyzer with ultra-low iridium loading , 2018, Applied Catalysis B: Environmental.

[18]  A. Ludwig,et al.  The stability number as a metric for electrocatalyst stability benchmarking , 2018, Nature Catalysis.

[19]  Lin-wang Wang,et al.  Tracking the Chemical and Structural Evolution of the TiS2 Electrode in the Lithium-Ion Cell Using Operando X-ray Absorption Spectroscopy. , 2018, Nano letters.

[20]  Sung Jong Yoo,et al.  Electrodeposited IrO2/Ti electrodes as durable and cost-effective anodes in high-temperature polymer-membrane-electrolyte water electrolyzers , 2018, Applied Catalysis B: Environmental.

[21]  E. Ticianelli,et al.  Effect of temperature on the activities and stabilities of hydrothermally prepared IrOx nanocatalyst layers for the oxygen evolution reaction , 2017 .

[22]  R. Schlögl,et al.  Reactive Electrophilic OI− Species Evidenced in High‐Performance Iridium Oxohydroxide Water Oxidation Electrocatalysts , 2017, ChemSusChem.

[23]  Qi Feng,et al.  A review of proton exchange membrane water electrolysis on degradation mechanisms and mitigation strategies , 2017 .

[24]  A. Aricò,et al.  The influence of iridium chemical oxidation state on the performance and durability of oxygen evolution catalysts in PEM electrolysis , 2017 .

[25]  G. Pacchioni,et al.  Increasing Oxide Reducibility: The Role of Metal/Oxide Interfaces in the Formation of Oxygen Vacancies , 2017 .

[26]  J. Watts,et al.  XPS investigation of monatomic and cluster argon ion sputtering of tantalum pentoxide , 2017 .

[27]  A. Grimaud,et al.  Activation of surface oxygen sites on an iridium-based model catalyst for the oxygen evolution reaction , 2016, Nature Energy.

[28]  Xue-qing Gong,et al.  OER activity manipulated by IrO6 coordination geometry: an insight from pyrochlore iridates , 2016, Scientific Reports.

[29]  R. Schlögl,et al.  Electrochemical Catalyst-Support Effects and Their Stabilizing Role for IrOx Nanoparticle Catalysts during the Oxygen Evolution Reaction. , 2016, Journal of the American Chemical Society.

[30]  J. Gascón,et al.  Iridium-based double perovskites for efficient water oxidation in acid media , 2016, Nature Communications.

[31]  K. Mayrhofer,et al.  Activity and stability of electrochemically and thermally treated iridium for the oxygen evolution reaction , 2016 .

[32]  R. Schlögl,et al.  The electronic structure of iridium and its oxides , 2016 .

[33]  Suk Woo Nam,et al.  Polarization characteristics of a low catalyst loading PEM water electrolyzer operating at elevated temperature , 2016 .

[34]  Suk Woo Nam,et al.  Development of electrodeposited IrO2 electrodes as anodes in polymer electrolyte membrane water electrolysis , 2015 .

[35]  R. Schlögl,et al.  Molecular Insight in Structure and Activity of Highly Efficient, Low-Ir Ir-Ni Oxide Catalysts for Electrochemical Water Splitting (OER). , 2015, Journal of the American Chemical Society.

[36]  A. Aricò,et al.  Nanosized IrOx and IrRuOx electrocatalysts for the O2 evolution reaction in PEM water electrolysers , 2015 .

[37]  Hong He,et al.  XAFS Study on the Specific Deoxidation Behavior of Iron Titanate Catalyst for the Selective Catalytic Reduction of NOx with NH3 , 2013 .

[38]  Jianguo Wang,et al.  An XAFS study on the specific microstructure of active species in iron titanate catalyst for NH3-SCR of NOx , 2013 .

[39]  L. Näslund,et al.  The Role of TiO2 Doping on RuO2-Coated Electrodes for the Water Oxidation Reaction , 2013 .

[40]  Min Gyu Kim,et al.  Anomalous decrease in structural disorder due to charge redistribution in Cr-doped Li4Ti5O12 negative-electrode materials for high-rate Li-ion batteries , 2012 .

[41]  Yuyan Shao,et al.  Oxygen Electrocatalysts for Water Electrolyzers and Reversible Fuel Cells: Status and Perspective , 2012 .

[42]  R. Kraehnert,et al.  Mesoporous IrO2 Films Templated by PEO-PB-PEO Block-Copolymers: Self-Assembly, Crystallization Behavior, and Electrocatalytic Performance , 2011 .

[43]  Michael F Toney,et al.  Lattice-strain control of the activity in dealloyed core-shell fuel cell catalysts. , 2010, Nature chemistry.

[44]  V. Antonucci,et al.  Preparation and characterization of titanium suboxides as conductive supports of IrO2 electrocatalysts for application in SPE electrolysers , 2009 .

[45]  Younan Xia,et al.  Controlling the Thickness of the Surface Oxide Layer on Cu Nanoparticles for the Fabrication of Conductive Structures by Ink‐Jet Printing , 2008 .

[46]  V. Luca,et al.  Structural and Electronic Properties of Sol−Gel Titanium Oxides Studied by X-ray Absorption Spectroscopy , 1998 .

[47]  A. Benedetti,et al.  Influence of the valve metal oxide on the properties of ruthenium based mixed oxide electrodes: Part I. Titanium supported RuO2/Ta2O5 layers , 1986 .

[48]  Robert Schlögl,et al.  Electrocatalytic Oxygen Evolution on Iridium Oxide: Uncovering Catalyst-Substrate Interactions and Active Iridium Oxide Species , 2014 .

[49]  D. Bélanger,et al.  Electrodeposition of iridium onto glassy carbon and platinum electrodes , 2012 .