Bifunctional Electrocatalysts for Overall and Hybrid Water Splitting

Chemical Reviews, Год журнала: 2024, Номер 124(7), С. 3694 - 3812

Опубликована: Март 22, 2024

Electrocatalytic water splitting driven by renewable electricity has been recognized as a promising approach for green hydrogen production. Different from conventional strategies in developing electrocatalysts the two half-reactions of (e.g., and oxygen evolution reactions, HER OER) separately, there growing interest designing bifunctional electrocatalysts, which are able to catalyze both OER. In addition, considering high overpotentials required OER while limited value produced oxygen, is another rapidly exploring alternative oxidation reactions replace hybrid toward energy-efficient generation. This Review begins with an introduction on fundamental aspects splitting, followed thorough discussion various physicochemical characterization techniques that frequently employed probing active sites, emphasis reconstruction during redox electrolysis. The design, synthesis, performance diverse based noble metals, nonprecious metal-free nanocarbons, overall acidic alkaline electrolytes, thoroughly summarized compared. Next, their application also presented, wherein anodic include sacrificing agents oxidation, pollutants oxidative degradation, organics upgrading. Finally, concise statement current challenges future opportunities presented hope guiding endeavors quest sustainable

Язык: Английский

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Unlocking the Transition of Electrochemical Water Oxidation Mechanism Induced by Heteroatom Doping

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(40)

Опубликована: Авг. 15, 2023

Abstract Heteroatom doping has emerged as a highly effective strategy to enhance the activity of metal‐based electrocatalysts toward oxygen evolution reaction (OER). It is widely accepted that does not switch OER mechanism from adsorbate (AEM) lattice‐oxygen‐mediated (LOM), and enhanced attributed optimized binding energies intermediates. However, this seems inconsistent with fact overpotential doped (<300 mV) considerably smaller than limit AEM (>370 mV). To determine origin inconsistency, we select phosphorus (P)‐doped nickel‐iron mixed oxides model observe enhances covalency metal‐oxygen bonds drive pathway transition LOM, thereby breaking adsorption linear relation between *OH *OOH in AEM. Consequently, obtained P‐doped display small 237 mV at 10 mA cm −2 . Beyond P, similar also observed on sulfur doping. These findings offer new insights into substantially originating heteroatom

Язык: Английский

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Lattice oxygen activation and local electric field enhancement by co-doping Fe and F in CoO nanoneedle arrays for industrial electrocatalytic water oxidation

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Фев. 3, 2024

Abstract Oxygen evolution reaction (OER) is critical to renewable energy conversion technologies, but the structure-activity relationships and underlying catalytic mechanisms in catalysts are not fully understood. We herein demonstrate a strategy promote OER with simultaneously achieved lattice oxygen activation enhanced local electric field by dual doping of cations anions. Rough arrays Fe F co-doped CoO nanoneedles constructed, low overpotential 277 mV at 500 mA cm −2 achieved. The dually doped could cooperatively tailor electronic properties CoO, leading improved metal-oxygen covalency stimulated activation. Particularly, induces synergetic effect tip enhancement proximity effect, which effectively concentrates OH − ions, optimizes barrier promotes O 2 desorption. This work demonstrates conceptual couple for effective electrocatalytic water oxidation.

Язык: Английский

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Ir Single Atoms Boost Metal–Oxygen Covalency on Selenide-Derived NiOOH for Direct Intramolecular Oxygen Coupling

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(10), С. 6846 - 6855

Опубликована: Фев. 29, 2024

This investigation probes the intricate interplay of catalyst dynamics and reaction pathways during oxygen evolution (OER), highlighting significance atomic-level local ligand structure insights in crafting highly active electrocatalysts. Leveraging a tailored ion exchange followed by electrochemical dynamic reconstruction, we engineered novel catalytic featuring single Ir atoms anchored to NiOOH (Ir1@NiOOH). approach involved strategic replacement Fe with Ir, facilitating transition selenide precatalysts into (oxy)hydroxides. elemental substitution promoted an upward shift O 2p band intensified metal–oxygen covalency, thereby altering OER mechanism toward enhanced activity. The from single-metal site (SMSM) dual-metal-site (DMSM) Ir1@NiOOH was substantiated situ differential mass spectrometry (DEMS) supported theoretical insights. Remarkably, electrode exhibited exceptional electrocatalytic performance, achieving overpotentials as low 142 308 mV at current densities 10 1000 mA cm–2, respectively, setting new benchmark for electrocatalysis OER.

Язык: Английский

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Hetero‐Anionic Structure Activated CoS Bonds Promote Oxygen Electrocatalytic Activity for High‐Efficiency Zinc–Air Batteries

Advanced Materials, Год журнала: 2023, Номер 35(36)

Опубликована: Май 18, 2023

Abstract The electronic structure of transition metal complexes can be modulated by replacing partial ion to obtain tuned intrinsic oxygen reduction reaction (ORR) or evolution (OER) electrocatalytic activity. However, the anion‐modulated ORR activity is still unsatisfactory, and construction hetero‐anionic remains challenging. Herein, an atomic doping strategy presented prepare CuCo 2 O 4‐x S x /NC‐2 (CCSO/NC‐2) as electrocatalysts, structrual characterization results favorably demonstrate substitution atoms for in CCSO/NC‐2, which shows excellent catalytic performance durability OER 0.1 m KOH. In addition, catalyst assembled Zinc–air battery with open circuit potential 1.43 V maintains after 300 h cyclic stability. Theoretical calculations differential charges illustrate that optimizes kinetics promotes electron redistribution. superior CCSO/NC‐2 catalysis mainly due its unique modulation main body. introduction CoO covalency constructs a fast transport channel, thus optimizing adsorption degree active site Co intermediates.

Язык: Английский

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Activating Lattice Oxygen in Spinel Oxides via Engineering Octahedral Sites for Oxygen Evolution

ACS Energy Letters, Год журнала: 2023, Номер 8(8), С. 3504 - 3511

Опубликована: Июль 26, 2023

Spinel oxides, representing an emerging class of highly active catalysts for oxygen evolution (OER), suffer from weak covalency metal d and p orbitals their typical crystal structure, which generally proceeds the OER with adsorbate mechanism (AEM) pathway. For activating lattice in spinel oxides to bypass scaling relationship limitation AEM, we herein grow sulfate salts on octahedral sites NiFe2O4 introduce Ni4+ cations Ni vacancies sites, exhibit remarkable performance overpotential 293 mV at 500 mA cm–2. Experiments theoretical calculations reveal that formation jointly enhance metal–oxygen hybridization strengthen bond both NiFeOOH phases, successfully triggering (LOM) pathway oxides.

Язык: Английский

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Electrosynthesis of α‐Amino Acids from NO and other NO_x species over CoFe alloy‐decorated Self‐standing Carbon Fiber Membranes

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(30)

Опубликована: Май 31, 2023

Abstract The conversion of industrial exhaust gases nitrogen oxides into high‐value products is significantly meaningful for global environment and human health. And green synthesis amino acids vital biomedical research sustainable development mankind. Herein, we demonstrate an innovative approach converting nitric oxide (NO) to a series α‐amino (over 13 kinds) through electrosynthesis with α‐keto over self‐standing carbon fiber membrane CoFe alloy. essential leucine exhibits high yield 115.4 μmol h −1 corresponding Faradaic efficiency 32.4 %, gram can be obtained within 24 hours in lab as well ultra‐long stability (>240 h) the catalyst, which could convert NO NH 2 OH rapidly attacking acid subsequent hydrogenation form acid. In addition, this method also suitable other sources including gaseous or liquidus 3 − . Therefore, work not only presents promising prospects from gas nitrate‐laden waste water products, but has significant implications synthetizing catalytic science.

Язык: Английский

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High‐Valence Metal‐Driven Electronic Modulation for Boosting Oxygen Evolution Reaction in High‐Entropy Spinel Oxide

Advanced Functional Materials, Год журнала: 2023, Номер 34(1)

Опубликована: Сен. 22, 2023

Abstract High‐entropy spinel oxides (HESOs) are a promising class of electrocatalysts whose material properties and catalytic activity can be finely tuned by controlling the elemental composition. Although numerous HESOs already reported, their compositions primarily limited to first‐row transition metals. Herein, synthesis high‐entropy (CrFeCoNiMo) 3 O 4 nanosheet (HEO‐NS) its application as oxygen evolution reaction (OER) catalyst reported. The displays low overpotential 255.3 mV at current density 10 mA cm −2 excellent stability, outperforming IrO 2 benchmark. Careful analysis with X‐ray photoelectron spectroscopy (XPS) absorption (XAS) reveals that incorporation high‐valence Cr Mo activate lattice weakening metal–oxygen bond promoting mechanism (LOM). Furthermore, achieve high 1 A 1.71 V in lab‐scale electrolyzer, demonstrating potential for practical application.

Язык: Английский

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Regulation of Atomic Fe‐Spin State by Crystal Field and Magnetic Field for Enhanced Oxygen Electrocatalysis in Rechargeable Zinc‐Air Batteries

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(28)

Опубликована: Май 4, 2023

Highly-active and low-cost bifunctional electrocatalysts for oxygen reduction evolution are essential in rechargeable metal-air batteries, single atom catalysts with Fe-N-C promising candidates. However, the activity still needs to be boosted, origination of spin-related catalytic performance is uncertain. Herein, an effective strategy regulate local spin state through manipulating crystal field magnetic proposed. The atomic Fe can regulated from low intermediate high spin. cavitation dxz dyz orbitals FeIII optimize O2 adsorption promote rate-determining step (*O2 *OOH). Benefiting these merits, electrocatalyst displays highest electrocatalytic activities. Furthermore, Fe-N-C-based zinc-air battery a power density 170 mW cm-2 good stability.

Язык: Английский

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IrCo Nanoparticles Encapsulated with Carbon Nanotubes for Efficient and Stable Acidic Water Splitting

ACS Catalysis, Год журнала: 2023, Номер 13(16), С. 10672 - 10682

Опубликована: Июль 31, 2023

The acidic water-splitting technology based on the polymer exchange membrane can produce hydrogen efficiently, continuously, and cleanly, which is expected to alleviate energy crisis. However, even noble metal-based electrocatalysts such as IrOx species would dissolve rapidly during oxygen evolution. Herein, we successfully assemble high-density carbon nanotubes (CNTs) encapsulated with IrCo nanoparticles (NPs) cloth (IrCo@CNT/CC) using a facile MOF-templated dicyandiamide-assisted pyrolysis strategy. Benefiting from favorable synergistic effect between Co Ir protection of CNT, obtained IrCo@CNT/CC only requires low cell voltage 1.500 V reach 10 mA cm–2 for water splitting an extremely loading 0.027 mg exhibits robust stability under continuous electrolysis 90 h in 0.5 M H2SO4, ranking it among one best bifunctional splitting. Detailed experiments reveal that CNT-encapsulated NPs remain after evolution reaction (HER) but transform into Co-doped IrO2 (OER). Further DFT simulation calculations confirm doping optimize their electronic structures lower barriers HER OER, respectively.

Язык: Английский

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