Hybridization State Transition under Working Conditions: Activity Origin of Single-Atom Catalysts

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(22), С. 15640 - 15647

Опубликована: Май 21, 2024

Single-atom catalysts (SACs) have been widely investigated and emerged as a transformative approach in electrocatalysis. Despite their clear structure, the origin of exceptional activity remains elusive. Herein, we elucidate common phenomenon hybridization state transition metal centers, which is responsible for across various SACs different reactions. Focusing on N-doped carbon-supported Ni SAC (NiN4 SAC) CO2 reduction reaction (CO2RR), our comprehensive computations successfully clarify under working conditions its relation with activity. This transition, triggered by intermediates applied potential, converts center from inert dsp2 to active d2sp3 state. Importantly, calculated selectivity CO2RR over d2sp3-hybridized are consistent experimental results, offering strong support proposed hypothesis. work suggests universal principle electronic structure evolution that could revolutionize catalyst design, also introduces new paradigm manipulating states enhance catalytic performance, implications reactions platforms.

Язык: Английский

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Salt Effect Engineering Single Fe‐N₂P₂‐Cl Sites on Interlinked Porous Carbon Nanosheets for Superior Oxygen Reduction Reaction and Zn‐Air Batteries

Advanced Science, Год журнала: 2024, Номер 11(12)

Опубликована: Янв. 15, 2024

Abstract Developing efficient metal‐nitrogen‐carbon (M‐N‐C) single‐atom catalysts for oxygen reduction reaction (ORR) is significant the widespread implementation of Zn‐air batteries, while synergic design matrix microstructure and coordination environment metal centers remains challenges. Herein, a novel salt effect‐induced strategy proposed to engineer N P coordinated atomically dispersed Fe atoms with extra‐axial Cl on interlinked porous carbon nanosheets, achieving superior catalyst (denoted as Fe‐NP‐Cl‐C) ORR batteries. The hierarchical nanosheet architecture can provide rapid mass/electron transfer channels facilitate exposure active sites. Experiments density functional theory (DFT) calculations reveal distinctive Fe‐N 2 ‐Cl sites afford significantly reduced energy barriers promoted kinetics ORR. Consequently, Fe‐NP‐Cl‐C exhibits distinguished performance half‐wave potential (E 1/2 ) 0.92 V excellent stability. Remarkably, assembled battery based delivers an extremely high peak power 260 mW cm −2 large specific capacity 812 mA h g −1 , outperforming commercial Pt/C most reported congeneric catalysts. This study offers new perspective structural optimization engineering electrocatalysis conversion devices.

Язык: Английский

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Progress of Pt and iron-group transition metal alloy catalysts with high ORR activity for PEMFCs

Journal of Electroanalytical Chemistry, Год журнала: 2024, Номер 959, С. 118165 - 118165

Опубликована: Март 9, 2024

Язык: Английский

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Electron Transfer from Encapsulated Fe₃C to the Outermost N‐Doped Carbon Layer for Superior ORR

Advanced Functional Materials, Год журнала: 2024, Номер 34(40)

Опубликована: Май 7, 2024

Abstract Encapsulating Fe 3 C in carbon layers has emerged as an innovative strategy for protecting while preserving its high oxygen reduction activity. However, fundamental questions persist regarding the active sites of encapsulated due to restricted accessibility molecules metal sites. Herein, intrinsic electron transfer mechanisms nanoparticles N‐doped materials are unveiled electrocatalysis. The precision‐structured 1 N material is used synthesize carbons with C, significantly enhancing catalytic activity (E ONSET = 0.98 V) and achieving near‐100% operational stability. In anion‐exchange membrane fuel cells, excellent peak power density 830 mW cm −2 reached at 60 °C. experimental computational results revealed that presence cores dynamically triggers outermost layer. This phenomenon amplifies reaction performance sites, contributing observed enhancement.

Язык: Английский

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Unraveling the Tandem Effect of Nitrogen Configuration Promoting Oxygen Reduction Reaction in Alkaline Seawater

Advanced Energy Materials, Год журнала: 2024, Номер 14(24)

Опубликована: Апрель 10, 2024

Abstract Developing seawater‐based high‐performance oxygen reduction reaction (ORR) electrocatalysts is meaningful to renewable energy storage and conversion, the Fe‐based derivatives encapsulated by nitrogen (N) doped carbon are typical representative. Nevertheless, unrevealing mechanism of N configuration ORR activity chlorine resistance still a great challenge. In this work, feasible strategy developed prepare controllable pyridinic/pyrrolic‐N carbon‐coated (Fe x N‐NC). Drawing support from H 3 PO 4 blocking based in situ Fourier transform infrared spectroscopy (FTIR) test density‐functional theory (DFT) calculation, tandem effect pyridinic‐N pyrrolic‐N on proved. Additionally, low hydrogen peroxide (H 2 O ) yield 4e − pathway Fe N‐NC demonstrate that doping effectively reduces adsorption Cl , which consistent with DFT. The half‐wave potential (E 1/2 for reaches 0.874 V alkaline seawater, ZABs assembled as air cathode deliver remarkable power density (162 mW cm −2 ), along excellent long‐term durability (>400 h).

Язык: Английский

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Local Oxidation Induced Amorphization of 1.5‐nm‐Thick Pt–Ru Nanowires Enables Superactive and CO‐Tolerant Hydrogen Oxidation in Alkaline Media

Advanced Functional Materials, Год журнала: 2023, Номер 33(43)

Опубликована: Июнь 19, 2023

Abstract Low‐dimensional amorphous metallic nanomaterials provide great possibility for creating high‐performance electrocatalysts owing to their conspicuous reacting merits derived from the flexible coordination structures, but remain extremely challenging in synthesis. Herein, this work reports a facile synthesis of carbon‐loaded 1.5‐nm‐thick Pt–Ru nanowires (NWs) through local oxidation induced amorphization process. During annealing premade crystalline NWs/C air, local‐oxidation oxyphilic Ru generates abundant random Ru–O bonds and disturbs order bimetallic lattices. The as‐prepared Pt 53 47 (a‐Pt ) exhibits an high activity (13.7 A mg −1 at 25 mV overpotential) excellent CO‐tolerance alkaline hydrogen reaction (HOR) electrocatalysis, drastically outperforming counterpart commercial benchmarks. Mechanism studies indicate effects as well rich disordered “Pt–Ru–O” and/or “Pt–O–Ru” atomic heterojunctions can weaken *H binding energy inversely strengthen *OH adsorption, thus promoting HOR kinetics. More uniquely, small interatomic spaces bond nets present H 2 /*H‐selected permeability, which spatially obstruct relatively larger CO molecules poison internal catalytic sites during HOR. CO‐shielded enriched surface jointly upgrade a‐Pt catalysts.

Язык: Английский

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Diatomic Iron with a Pseudo-Phthalocyanine Coordination Environment for Highly Efficient Oxygen Reduction over 150,000 Cycles

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(36), С. 24842 - 24854

Опубликована: Авг. 26, 2024

Atomically dispersed Fe-N-C catalysts emerged as promising alternatives to commercial Pt/C for the oxygen reduction reaction. However, majority of showed unsatisfactory activity and durability due their inferior O-O bond-breaking capability rapid Fe demetallization. Herein, we create a pseudo-phthalocyanine environment coordinated diatomic iron (Fe

Язык: Английский

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Recent advances in Fe‐N‐C single‐atom site coupled synergistic catalysts for boosting oxygen reduction reaction

Electron, Год журнала: 2024, Номер 2(1)

Опубликована: Фев. 1, 2024

Abstract Metal–air batteries, fuel cells, and electrochemical H 2 O production currently attract substantial consideration in the energy sector owing to their efficiency eco‐consciousness. However, broader use is hindered by complex oxygen reduction reaction (ORR) that occurs at cathodes involves intricate electron transfers. Despite significant ORR performance of platinum‐based catalysts, high cost, operational limitations, susceptibility methanol poisoning hinder implementation. This emphasizes need for efficient non‐precious metal‐based electrocatalysts. A promising approach utilizing single‐atom catalysts (SACs) featuring metal–nitrogen–carbon (M‐N‐C) coordination sites. SACs offer advantages such as optimal utilization metal atoms, uniform active centers, precisely defined catalytic sites, robust metal–support interactions. symmetrical distribution around central atom a site (M‐N 4 ) often results suboptimal performance. challenge can be addressed carefully tailoring surrounding environment center. review specifically focuses on recent advancements Fe‐N within Fe‐N‐C SACs. It highlights strategy coupling sites with clusters and/or nanoparticles, which enhances intrinsic activity. By capitalizing interplay between associated species, overall improved. The combines findings from experimental studies density functional theory simulations, covering synthesis strategies coupled synergistic characterization techniques, influence particles offering comprehensive outlook, aims encourage research into high‐efficiency Fe real‐world applications coming years.

Язык: Английский

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Recent Progress and Prospects of Manganese–Nitrogen–Carbon Electrocatalysts for Oxygen Reduction Reaction

Energy & Fuels, Год журнала: 2024, Номер 38(12), С. 10589 - 10612

Опубликована: Июнь 7, 2024

The oxygen reduction reaction (ORR) holds significant importance in the electrochemical processes of energy conversion systems. kinetics ORR are sluggish as it is involved multistep reactions. It imperative to investigate electrocatalysts with outstanding performance and durability accelerating their kinetics. Manganese–nitrogen–carbon (Mn–N–C) materials offer advantages including efficient atom utilization easily tunable coordination structures, rendering them promising candidates for enhancing catalytic activity. mini-review provides a concise overview fundamental principles underlying ORR. Then, three strategies regulating structure summarized improve activity Mn–N–C catalysts: adjusting number N atoms around Mn atoms, doping nonmetal metal atoms. Finally, this outlines challenges prospects associated catalyst This anticipated deepen comprehension readers by presenting targeted optimization methods regulate configuration catalysts.

Язык: Английский

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Refining Asymmetric Low‐Coordinated Fe‐N₃ Motif to Boost Catalytic Ozonation Activity

Advanced Functional Materials, Год журнала: 2024, Номер 34(26)

Опубликована: Фев. 28, 2024

Abstract In the quest to boost intrinsic activity of single‐atom catalysts (SACs), optimizing electronic properties metal centers and maximizing active sites play a pivotal role. Here, facile surface molten salt‐assisted approach for fabricating porous iron‐nitrogen‐carbon enriched with catalytically accessible motifs is reported. Multiple characterization analyses prove that abundant defects are generated at edge sites, resulting in formation thermally stable unstitched Fe‐N 3 motif. Theoretical investigations unveil transition from 4 induces structural alteration, convergence Fe‐3 d orbital energy Fermi energy. The low‐coordinated motif exhibits higher activation ability, reinforcing its interaction O weakening O‐O bond. This leads reduction reactivity atomic oxygen barriers (O ‐to‐*O/*OO), ultimately achieving efficient catalytic oxidation methyl mercaptan intermediates, performance 20‐fold than intact 625‐fold commercial MnO 2 . These findings present comprehensive synthesizing SACs fully boosted configurations advance ozonation activity.

Язык: Английский

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