MIL‐101‐Derived Mesoporous Carbon Supporting Highly Exposed Fe Single‐Atom Sites as Efficient Oxygen Reduction Reaction Catalysts

Advanced Materials, Год журнала: 2021, Номер 33(23)

Опубликована: Апрель 29, 2021

Abstract Fe single‐atom catalysts (Fe SACs) with atomic FeN x active sites are very promising alternatives to platinum‐based for the oxygen reduction reaction (ORR). The pyrolysis of metal–organic frameworks (MOFs) is a common approach preparing SACs, though most MOF‐derived reported date microporous and thus suffer from poor mass transfer high proportion catalytically inaccessible sites. Herein, NH 2 ‐MIL‐101(Al), MOF possessing mesoporous cage architecture, used as precursor prepare series N‐doped carbon supports (denoted herein NC‐MIL101‐T) well‐defined structure at different temperatures. NC‐MIL101‐T then impregnated Fe(II)‐phenanthroline complex, heated again yield SAC‐MIL101‐T rich in accessible single atom best performing SAC‐MIL101‐1000 catalyst offers outstanding ORR activity alkaline media, evidenced by an half‐wave potential 0.94 V (vs RHE) 0.1 m KOH, well excellent performance both aqueous primary zinc–air batteries (a near maximum theoretical energy density 984.2 Wh kg Zn −1 ) solid‐state peak power 50.6 mW cm −2 specific capacity 724.0 mAh ).

Язык: Английский

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Metal–Organic Frameworks Derived Functional Materials for Electrochemical Energy Storage and Conversion: A Mini Review

Nano Letters, Год журнала: 2021, Номер 21(4), С. 1555 - 1565

Опубликована: Фев. 11, 2021

With many apparent advantages including high surface area, tunable pore sizes and topologies, diverse periodic organic–inorganic ingredients, metal–organic frameworks (MOFs) have been identified as versatile precursors or sacrificial templates for preparing functional materials advanced electrodes high-efficiency catalysts electrochemical energy storage conversion (EESC). In this Mini Review, we first briefly summarize the material design strategies to show rich possibilities of chemical compositions physical structures MOFs derivatives. We next highlight latest advances focusing on composition/structure/performance relationship discuss their practical applications in various EESC systems, such supercapacitors, rechargeable batteries, fuel cells, water electrolyzers, carbon dioxide/nitrogen reduction reactions. Finally, provide some our own insights into major challenges prospective solutions MOF-derived EESC, hoping shed light future development highly exciting field.

Язык: Английский

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Superiority of Dual‐Atom Catalysts in Electrocatalysis: One Step Further Than Single‐Atom Catalysts

Advanced Energy Materials, Год журнала: 2022, Номер 12(9)

Опубликована: Янв. 18, 2022

Abstract In recent years, dual‐atom catalysts (DACs) have attracted extensive attention, as an extension of single‐atom (SACs). Compared with SACs, DACs higher metal loading and more complex flexible active sites, thus achieving better catalytic performance providing opportunities for electrocatalysis. This review introduces the research progress in years on how to design new enhance Firstly, advantages increasing are introduced. Then, role changing adsorption condition reactant molecules atoms is discussed. Moreover, ways which can reduce reaction energy barrier key steps change path explored. Catalytic applications different electrocatalytic reactions, including carbon dioxide reduction reaction, oxygen evolution hydrogen nitrogen followed. Finally, a brief summary made challenges prospects

Язык: Английский

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An Adjacent Atomic Platinum Site Enables Single‐Atom Iron with High Oxygen Reduction Reaction Performance

Angewandte Chemie International Edition, Год журнала: 2021, Номер 60(35), С. 19262 - 19271

Опубликована: Июнь 22, 2021

Abstract The modulation effect has been widely investigated to tune the electronic state of single‐atomic M‐N‐C catalysts enhance activity oxygen reduction reaction (ORR). However, in‐depth study is rarely reported for isolated dual‐atomic metal sites. Now, catalytic activities Fe‐N 4 moiety can be enhanced by adjacent Pt‐N through effect, in which acts as modulator 3d orbitals active site and optimize ORR activity. Inspired this principle, we design synthesize electrocatalyst that comprises /Pt‐N moieties dispersed nitrogen‐doped carbon matrix (Fe‐N @NC) exhibits a half‐wave potential 0.93 V vs. RHE negligible degradation (ΔE 1/2 =8 mV) after 10000 cycles 0.1 M KOH. We also demonstrate not effective optimizing performances Co‐N Mn‐N systems.

Язык: Английский

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Iron atom–cluster interactions increase activity and improve durability in Fe–N–C fuel cells

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Май 26, 2022

Simultaneously increasing the activity and stability of single-atom active sites M-N-C catalysts is critical but remains a great challenge. Here, we report an Fe-N-C catalyst with nitrogen-coordinated iron clusters closely surrounding Fe-N4 for oxygen reduction reaction in acidic fuel cells. A strong electronic interaction built between satellite due to unblocked electron transfer pathways very short interacting distances. The optimize adsorption strength intermediates on also shorten bond amplitude incoherent vibrations. As result, both are increased by about 60% terms turnover frequency demetalation resistance. This work shows potential interactions multiphase metal species improvements catalysts.

Язык: Английский

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Atomically Dispersed Co₂–N₆ and Fe–N₄ Costructures Boost Oxygen Reduction Reaction in Both Alkaline and Acidic Media

Advanced Materials, Год журнала: 2021, Номер 33(49)

Опубликована: Окт. 8, 2021

Abstract Polynary transition‐metal atom catalysts are promising to supersede platinum (Pt)‐based for oxygen reduction reaction (ORR). Regulating the local configuration of atomic is key catalyst performance enhancement. Different from previously reported single‐atom or dual‐atom configurations, a new type ternary‐atom catalyst, which consists atomically dispersed, nitrogen‐coordinated Co–Co dimers, and Fe single sites (i.e., Co 2 –N 6 Fe–N 4 structures) that coanchored on highly graphitized carbon supports developed. This unique ORR outperforms with only in both alkaline acid conditions. Density functional theory calculations clearly unravels synergistic effect sites, can induce higher filling degree Fe–d orbitals favors binding capability *OH intermediates (the rate determining step). may be alternative Pt drive cathodic zinc–air batteries.

Язык: Английский

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Emerging low-nuclearity supported metal catalysts with atomic level precision for efficient heterogeneous catalysis

Nano Research, Год журнала: 2022, Номер 15(9), С. 7806 - 7839

Опубликована: Июнь 2, 2022

Язык: Английский

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Fe Single‐Atom Catalysts on MOF‐5 Derived Carbon for Efficient Oxygen Reduction Reaction in Proton Exchange Membrane Fuel Cells

Advanced Energy Materials, Год журнала: 2021, Номер 12(3)

Опубликована: Дек. 15, 2021

Abstract The development of Fe single‐atom catalysts (Fe SACs) with abundant, accessible sites is a key step toward enhancing the efficiency oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). In this study, Zn 4 O(1,4‐benzenedicarboxylate) 3 (MOF‐5), which has 3D microporous cubic structure, used as precursor to prepare highly‐porous carbon (denoted C‐MOF‐5) an ultrahigh specific surface area (2751 m 2 g –1 ) and high external (1651 ). C‐MOF‐5 demonstrated effective support yield SAC‐MOF‐5 large amount FeN x (2.35 wt%). delivers half‐wave potential 0.83 V (vs RHE) 0.5 H SO electrolyte, achieves peak power density 0.84 W cm –2 0.2 MPa ‐O PEMFC. This excellent performance originates from for formation single atoms, increased exposure active sites. work may inspire rational design metal derived wider range MOF precursors improve PEMFCs.

Язык: Английский

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Lightweight, Fire‐Retardant, and Anti‐Compressed Honeycombed‐Like Carbon Aerogels for Thermal Management and High‐Efficiency Electromagnetic Absorbing Properties

Small, Год журнала: 2021, Номер 17(33)

Опубликована: Июль 11, 2021

Abstract Ordered porous carbon materials (PCMs) have potential applications in various fields due to their low mass densities and features. However, it yet remains extremely challenging construct PCMs with multifunctionalization for electromagnetic wave absorption. Herein, the honeycombed‐like aerogels embedded Co@C nanoparticles are fabricated by a directionally freeze‐casting carbonization method. The optimized aerogel possesses density (0.017 g cm −3 ), fire‐retardant, robust mechanical performance (compression moduli reach 1411 420 kPa longitudinal transverse directions at 80% strain, respectively), high thermal management (high insulation capability high‐efficiency electrothermal conversion ability). Notably, exhibits excellent absorption properties broad effective bandwidth (13.12–17.14 GHz) strong (−45.02 dB) thickness of only 1.5 mm. Density functional theory calculations experimental results demonstrate that stem from synergetic effects among electrical conductivity, numerous interfaces dipoles unique ordered structure. Meanwhile, computer simulation technology (CST) confirms multifunctional can attenuate more energy practical environment. This work paves way rational design fabrication next‐generation absorbing materials.

Язык: Английский

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Ordered Macroporous Carbonous Frameworks Implanted with CdS Quantum Dots for Efficient Photocatalytic CO₂ Reduction

Advanced Materials, Год журнала: 2021, Номер 33(35)

Опубликована: Июль 24, 2021

Abstract Solar‐driven photocatalytic CO 2 reduction is regarded as a promising way to simultaneously mitigate the energy crisis and pollution. However, achieving high efficiency of reduction, especially without assistance sacrifice reagents or extra alkaline additives, remains critical issue. Herein, photocatalyst 3D ordered macroporous N‐doped carbon (NC) supported CdS quantum dots (3DOM CdSQD/NC) successfully fabricated toward via an in situ transformation strategy. Additionally, amines oxidation reaction introduced replace H O process further boost efficiency. Impressively, 3DOM CdSQD/NC exhibits superior activity selectivity coupled with oxidation, affording production rate 5210 µmol g −1 h absence any sacrificial agents additives. Moreover, achieves apparent 2.9% at 450 nm. Mechanism studies indicate that macropores NC matrix are beneficial transfer photogenerated carriers. Furthermore, highly dispersed QDs on skeleton able significantly promote adsorption both amine molecules depress activation barriers by stabilizing *COOH intermediate, directly contributing activity.

Язык: Английский

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