Enhancing Oxygen Evolution Reaction by Simultaneously Triggering Metal and Lattice Oxygen Redox Pair in Iridium Loading on Ni‐Doped Co₃O₄

Advanced Energy Materials, Год журнала: 2023, Номер 13(43)

Опубликована: Окт. 2, 2023

Abstract Since the active sites in catalytic systems are either metal or lattice oxygen, simultaneously triggering and oxygen redox pair with low energy barriers is expected to provide diversified efficient accelerate evolution reaction (OER) kinetics, but this a great challenge. Herein, Ir species (Ir clusters single atoms) loaded on Ni‐doped Co 3 O 4 designed (Ir/Ni‐Co ), where metallic downsize spread into high‐density atoms load reconstruction‐derived CoOOH. In situ spectroscopy, isotope‐labeled, chemical probe experiments demonstrate that site activated participate OER. Further theoretical studies most favorable promote OER through an adsorbate mechanism barrier of 1.69 eV. The Ni cooperating synergistically upshifts positions p band centers. Thus, bridges via coupling adsorbed fulfill O─O bond formation. Benefiting from conjoint participation pair, Ir/Ni‐Co affords extremely overpotentials 177 263 mV at corresponding 10 500 mA cm −2 .

Язык: Английский

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Iron‐Induced Localized Oxide Path Mechanism Enables Efficient and Stable Water Oxidation

Angewandte Chemie International Edition, Год журнала: 2024, Номер unknown

Опубликована: Ноя. 6, 2024

Abstract The sluggish reaction kinetics of the anodic oxygen evolution (OER) and inadequate catalytic performance non‐noble metal‐based electrocatalysts represent substantial barriers to development anion exchange membrane water electrolyzer (AEMWE). This study performed synthesis a three‐dimensional (3D) nanoflower‐like electrocatalyst (CFMO) via simple one‐step method. substitution Co with Fe in structure induces localized oxide path mechanism (LOPM), facilitating direct O−O radical coupling for enhanced O 2 evolution. optimized CFMO‐2 demonstrates superior OER performance, achieving an overpotential 217 mV at 10 mA cm −2 , alongside exceptional long‐term stability minimal degradation after 1000 h operation 1.0 M KOH. These properties surpass most conventional noble electrocatalysts. Furthermore, assembled AEMWE system, utilizing CFMO‐2, operates cell voltage 1.65 V deliver A . In situ characterizations reveal that, addition traditional adsorbate (AEM) isolated sites, new LOPM occurred around bimetallic sites. First‐principles calculations confirm greatly reduced energy barriers. work highlights potential improving design AEMWE.

Язык: Английский

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Ni and Co Active Site Transition and Competition in Fluorine‐Doped NiCo(OH)₂ LDH Electrocatalysts for Oxygen Evolution Reaction

Small, Год журнала: 2024, Номер 20(31)

Опубликована: Март 18, 2024

Abstract The oxygen evolution reaction (OER) performance of NiCo LDH electrocatalysts can be improved through fluorine doping. roles Ni and Co active sites in such catalysts remain ambiguous controversial. In addressing the issue, this study draws upon molecular orbital theory proposes center competitive mechanism between Co. doped F‐atoms directly impact valence state metal atoms or exert an indirect influence dehydrogenation, thereby modulating center. As are progressively aggregate, e g orbitals transition from 2 to 1 , subsequently 0 . corresponding elevates +2 +3, then +4, signifying initial increase followed by a subsequent decrease electrocatalytic performance. Furthermore, series F‐NiCo synthesized verify occupancy analysis, catalytic OER overpotentials 303, 243, 240, 246 mV at current density 10 mA cm −2 respectively, which coincides well with theoretical prediction. This investigation not only provides novel mechanistic insights into competition but also establishes foundation for design high‐performance catalysts.

Язык: Английский

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Achieving superior oxygen evolution of perovskite via phase transition and electrochemical reconstruction strategy

Energy & Environmental Science, Год журнала: 2024, Номер 17(12), С. 4044 - 4054

Опубликована: Янв. 1, 2024

We propose a strategy of phase transformation and electrochemical reconstruction to improve the OER performance perovskite oxides. The Ru SA -Co 3 O 4 /CoOOH catalyst exhibits an ultra-low overpotential 175 mV at 10 mA cm −2 , superior previously reported perovskite-derived electrocatalysts.

Язык: Английский

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Cation vacancies creation propel pre-oxidation enhancing nickel hydroxide activity for highly efficient 5-hydroxymethylfurfural upgrading

Applied Catalysis B Environment and Energy, Год журнала: 2024, Номер 347, С. 123785 - 123785

Опубликована: Апрель 24, 2024

Язык: Английский

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