Atomically dispersed hexavalent iridium oxide from MnO ₂ reduction for oxygen evolution catalysis

Science, Год журнала: 2024, Номер 384(6696), С. 666 - 670

Опубликована: Май 9, 2024

Hexavalent iridium (Ir

Язык: Английский

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Cerium Dioxide as an Electron Buffer to Stabilize Iridium for Efficient Water Electrolysis

Advanced Functional Materials, Год журнала: 2024, Номер 34(34)

Опубликована: Март 20, 2024

Abstract Sustaining the steady state for highly active non‐stoichiometric iridium (Ir)‐based oxide (IrO x ) at low Ir loading remains challenging primarily due to continuous oxidation and sequent dissolution of sites during oxygen evolution reaction (OER). In this context, a new iridium–cerium (Ce) substitution solid solution (SSO) has been developed, featuring uniformly dispersed atoms within Ce dioxide (CeO 2 matrix as electron buffer, which delivers remarkable acidic OER catalytic activity enhanced stability. The electron‐buffering capacity CeO facilitates charge transfer toward atoms, leading abundant low‐valence effectively prevent their dissolution. As result, Ir─Ce SSO demonstrates an overpotential merely 238 mV@10 mA cm −2 . Proton exchange membrane water electrolyzer employing 396 µg operates consistently over 100 h@500 Density functional theory (DFT) calculations corroborate that effect enriches density III substantially increases energy barrier atoms. This study presents viable approach addressing issues instability efficiency in Ir‐based electrocatalysts electrolysis.

Язык: Английский

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Theoretical Prediction and Experimental Verification of IrO_x Supported on Titanium Nitride for Acidic Oxygen Evolution Reaction

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(24), С. 16499 - 16510

Опубликована: Июнь 11, 2024

Reducing iridium (Ir) catalyst loading for acidic oxygen evolution reaction (OER) is a critical strategy large-scale hydrogen production via proton exchange membrane (PEM) water electrolysis. However, simultaneously achieving high activity, long-term stability, and reduced material cost remains challenging. To address this challenge, we develop framework by combining density functional theory (DFT) prediction using model surfaces proof-of-concept experimental verification thin films nanoparticles. DFT results predict that oxidized Ir monolayers over titanium nitride (IrOx/TiN) should display higher OER activity than IrOx while reducing loading. This verified depositing TiN physical vapor deposition. The promising film are then extended to commercially viable powder IrOx/TiN catalysts, which demonstrate lower overpotential mass commercial IrO2 stability of 250 h maintain current 10 mA cm–2. superior performance further confirmed electrolyzer (PEMWE), shows cell voltage achieve 1 A Both in situ X-ray absorption spectroscopy reveal the strongly depends on IrOx-TiN interaction direct Ir–Ti bonding. study highlights importance close between theoretical based mechanistic understanding catalysts facilitate development more practical with OER.

Язык: Английский

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Dynamic Redox Induced Localized Charge Accumulation Accelerating Proton Exchange Membrane Electrolysis

Advanced Materials, Год журнала: 2025, Номер unknown

Опубликована: Янв. 2, 2025

The sluggish anodic oxygen evolution reaction (OER) in proton exchange membrane (PEM) electrolysis necessitates applied bias to facilitate electron transfer as well bond cleavage and formation. Traditional electrocatalysis focuses on analyzing the effects of transfer, while role charge accumulation induced by overpotential has not been thoroughly investigated. To explore influence mechanism bias-driven accumulation, capacitive Mn is incorporated into IrO

Язык: Английский

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Proton Exchange Membrane Water Splitting: Advances in Electrode Structure and Mass‐Charge Transport Optimization

Advanced Materials, Год журнала: 2025, Номер unknown

Опубликована: Март 4, 2025

Abstract Proton exchange membrane water electrolysis (PEMWE) represents a promising technology for renewable hydrogen production. However, the large‐scale commercialization of PEMWE faces challenges due to need acid oxygen evolution reaction (OER) catalysts with long‐term stability and corrosion‐resistant electrode assemblies (MEA). This review thoroughly examines deactivation mechanisms acidic OER crucial factors affecting assembly instability in complex environments, including catalyst degradation, dynamic behavior at MEA triple‐phase boundary, equipment failures. Targeted solutions are proposed, improvements, optimized designs, operational strategies. Finally, highlights perspectives on strict activity/stability evaluation standards, situ/operando characteristics, practical electrolyzer optimization. These insights emphasize interrelationship between catalysts, MEAs, activity, stability, offering new guidance accelerating systems.

Язык: Английский

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Durable MnO2 electrocatalysts by stronger Mn–O bonds

Nature Catalysis, Год журнала: 2024, Номер 7(3), С. 227 - 228

Опубликована: Март 26, 2024

Язык: Английский

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Engineering Ir-based catalysts for high current density applications in proton exchange membrane water electrolyzers

Energy & Environmental Science, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 27, 2024

Catalysts engineering focusing on industrialization, bridging the gap between academic research and industrial demands.

Язык: Английский

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NdMn1.5Ru0.5O5, a high-performance electrocatalyst with low Ru content for acidic oxygen evolution reaction

Journal of Power Sources, Год журнала: 2024, Номер 604, С. 234416 - 234416

Опубликована: Апрель 6, 2024

A mixed oxide with the crystal structure of DyMn2O5 family, namely NdMn1.5Ru0.5O5, is reported active for oxygen evolution reaction (OER) in acidic media. NdMn1.5Ru0.5O5 displays high OER activity 500 gRu−1 at 1.5 V. Moreover, more stable than most Ru oxides to date, remaining cycles between 1.1. and 1.7 V low scan rate 10 mV s−1. The stability are attributed cations, as NdMn2O5 exhibits very activity. has particularly short Ru–Ru distances 2.60 Å, a value close metallic around 2.642 Å. durability also demonstrated proton exchange membrane water electrolysis cell by producing low-loaded anode electrode 0.5 mgRucm−2. achieves 1.97 cm−2, consistent performances Ru-based catalysts but lower loading. This performance maintained during 100 h operation. Additionally, visible ORR media, recording an onset potential 0.85 0.1 mA cm−2. It noteworthy highlight extreme rarity bifunctional ORR/OER

Язык: Английский

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Self-templated synthesis of Ni3S2@NiCoN with core-shell structure for effective hydrogen evolution reaction

International Journal of Hydrogen Energy, Год журнала: 2024, Номер 59, С. 1419 - 1426

Опубликована: Фев. 15, 2024

Язык: Английский

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Dynamics of Highly Active Ln₃IrO₇ Catalysts for the Oxygen Evolution Reaction in Acid

Advanced Energy Materials, Год журнала: 2024, Номер 14(47)

Опубликована: Авг. 29, 2024

Abstract An improved understanding of catalyst dynamics for the oxygen evolution reaction (OER) in acid is critical informing development highly efficient, stable, and cost‐effective OER catalysts proton exchange membrane water electrolysis applications. Herein tunable, active, dynamic Ir 5+ materials are studied, Ln 3 IrO 7 (Ln = Pr, Nd, Sm, Eu). Leveraging a combination situ ex characterization, as well an advanced mercury underpotential deposition technique surface site quantification, nature throughout electrochemical activation under conditions characterized. The trends elucidated between intrinsic activity, quantity, metal dissolution behavior tuned by site's atomic number. A relationship uncovered to show that maintenance excellent activity performance testing correlated with catalysts’ ability preserve high degree enrichment, where heightened stability sites interestingly parallels reduced testing. It found number decreased, materials’ improves, due increased thermodynamic driving force dissolution, which hypothesized enable active Ir‐based motifs.

Язык: Английский

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