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

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: May 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.

Language: Английский

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Switching the Oxygen Evolution Mechanism on Atomically Dispersed Ru for Enhanced Acidic Reaction Kinetics

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(43), P. 23659 - 23669

Published: Oct. 23, 2023

Designing stable single-atom electrocatalysts with lower energy barriers is urgent for the acidic oxygen evolution reaction. In particular, atomic catalysts are highly dependent on kinetically sluggish acid-base mechanism, limiting reaction paths of intermediates. Herein, we successfully manipulate steric localization Ru single atoms at Co3O4 surface to improve by precise control anchor sites. The delicate structure design can switch mechanism from lattice (LOM) optimized adsorbate (AEM). embedded into cation vacancies reveal an that activates proton donor-acceptor function (PDAM), demonstrating a new catalytic pathway circumvent classic scaling relationship. Steric interactions intermediates anchored Ru-O-Co interface played primary role in optimizing intermediates' conformation and reducing barrier. As comparison, confined sites exhibit process. result, atom spatial position presents 100-fold increase mass activity 36.96 A gRu(ads)-1 4012.11 gRu(anc)-1 1.50 V. These findings offer insights behavior.

Language: Английский

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Rapid complete reconfiguration induced actual active species for industrial hydrogen evolution reaction

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Oct. 2, 2022

Rational regulation of electrochemical reconfiguration and exploration activity origin are important foundations for realizing the optimization electrocatalyst activity, but rather challenging. Herein, we potentially develop a rapid complete strategy heterostructures CoC2O4 coated by MXene nanosheets (CoC2O4@MXene) during hydrogen evolution reaction (HER) process. The self-assembled CoC2O4@MXene nanotubular structure has high electronic accessibility abundant electrolyte diffusion channels, which favor reconfiguration. Such creates new actual catalytic active species Co(OH)2 transformed from CoC2O4, is coupled with to facilitate charge transfer decrease free energy Volmer step toward fast HER kinetics. reconfigured components require low overpotentials 28 216 mV at 10 1000 mA cm-2 in alkaline conditions decent stability natural seawater. This work gives insights understanding formation opens up way high-performance electrocatalysts.

Language: Английский

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Pinpointing the axial ligand effect on platinum single-atom-catalyst towards efficient alkaline hydrogen evolution reaction

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Nov. 12, 2022

Developing active single-atom-catalyst (SAC) for alkaline hydrogen evolution reaction (HER) is a promising solution to lower the green cost. However, correlations are not clear between chemical environments around active-sites and their desired catalytic activity. Here we study group of SACs prepared by anchoring platinum atoms on NiFe-layered-double-hydroxide. While maintaining homogeneity Pt-SACs, various axial ligands (-F, -Cl, -Br, -I, -OH) employed via facile irradiation-impregnation procedure, enabling us discover definite chemical-environments/performance correlations. Owing its high first-electron-affinity, chloride chelated Pt-SAC exhibits optimized bindings with hydroxide, which favor sluggish water dissociation further promote HER. Specifically, it shows mass-activity 30.6 A mgPt-1 turnover frequency 30.3 H2 s-1 at 100 mV overpotential, significantly higher than those state-of-the-art Pt-SACs commercial Pt/C catalyst. Moreover, energy efficiency 80% obtained electrolyser assembled using above catalyst under practical-relevant conditions.

Language: Английский

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Construction of Co₄ Atomic Clusters to Enable Fe−N₄ Motifs with Highly Active and Durable Oxygen Reduction Performance

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(30)

Published: May 24, 2023

Abstract Fe−N−C catalysts with single‐atom Fe−N 4 configurations are highly needed owing to the high activity for oxygen reduction reaction (ORR). However, limited intrinsic and dissatisfactory durability have significantly restrained practical application of proton‐exchange membrane fuel cells (PEMFCs). Here, we demonstrate that constructing adjacent metal atomic clusters (ACs) is effective in boosting ORR performance stability catalysts. The integration uniform Co ACs on N‐doped carbon substrate (Co @/Fe 1 @NC) realized through a “pre‐constrained” strategy using molecular Fe(acac) 3 implanted precursors. as‐developed @NC catalyst exhibits excellent half‐wave potential ( E 1/2 ) 0.835 V vs. RHE acidic media peak power density 840 mW cm −2 H 2 −O cell test. First‐principles calculations further clarify catalytic mechanism identified modified ACs. This work provides viable precisely establishing atomically dispersed polymetallic centers efficient energy‐related catalysis.

Language: Английский

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Progress and challenges in electrochemical energy storage devices: Fabrication, electrode material, and economic aspects

Chemical Engineering Journal, Journal Year: 2023, Volume and Issue: 468, P. 143706 - 143706

Published: May 24, 2023

Language: Английский

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High‐Loading Co Single Atoms and Clusters Active Sites toward Enhanced Electrocatalysis of Oxygen Reduction Reaction for High‐Performance Zn–Air Battery

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 33(4)

Published: Nov. 18, 2022

Abstract The development of precious‐metal alternative electrocatalysts for oxygen reduction reaction (ORR) is highly desired a variety fuel cells, and single atom catalysts (SACs) have been envisaged to be the promising choice. However, there remains challenges in synthesis high metal loading SACs (>5 wt.%), thus limiting their electrocatalytic performance. Herein, facile self‐sacrificing template strategy developed fabricating Co atoms along with atomic clusters co‐anchored on porous‐rich nitrogen‐doped graphene (Co SAs/AC@NG), which implemented by pyrolysis dicyandiamide formation layered g‐C 3 N 4 as sacrificed templates, providing rich anchoring sites achieve up 14.0 wt.% SAs/AC@NG. Experiments combined density functional theory calculations reveal that co‐existence underlying nitrogen doped carbon optimized 40 SAs/AC@NG synergistically contributes enhanced electrocatalysis ORR, outperforms state‐of‐the‐art Pt/C presenting half‐wave potential ( E 1/2 = 0.890 V) robust long‐term stability. Moreover, presents excellent performance Zn–air battery high‐peak power (221 mW cm −2 ) strong cycling stability, demonstrating great energy storage applications.

Language: Английский

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Modulating Local Interfacial Bonding Environment of Heterostructures for Energy‐Saving Hydrogen Production at High Current Densities

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(12)

Published: Jan. 8, 2023

Abstract Coupling urea oxidation reaction (UOR) with hydrogen evolution (HER) is an effective energy‐saving technique for generation. However, exploring efficient bifunctional electrocatalysts under high current density still challenging. Herein, hierarchical Fe doped cobalt selenide coupled FeCo layered double hydroxide (Fe‐Co 0.85 Se/FeCo LDH) array as a self‐supported superior heterojunction electrode rationally designed both UOR and HER. The unique heterostructure facilitates electron transfer interface interactions through local interfacial Co‐Se/O‐Fe bonding environment modulation, improving kinetics intrinsic activity. As result, the heterostructured electrocatalyst exhibits ultralow potentials of −0.274 1.48 V to reach 500 mA cm −2 catalyzing HER UOR, respectively. Particularly, full electrolysis system driven by Fe‐Co LDH delivers 300 at relatively low potential 1.57 V, which 150 mV lower than conventional water electrolysis. combination in situ characterization theoretical analysis reveal that active sites adjustable electronic are induced heterojunction, facilitating decomposition stabilization intermediates UOR. This work inspires modulation optimize advanced H 2 production.

Language: Английский

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Carbon Nanocage with Maximum Utilization of Atomically Dispersed Iron as Efficient Oxygen Electroreduction Nanoreactor

Advanced Materials, Journal Year: 2022, Volume and Issue: 35(5)

Published: Nov. 9, 2022

As key parameters of electrocatalysts, the density and utilization active sites determine electrocatalytic performance toward oxygen reduction reaction. Unfortunately, prevalent electrocatalysts fail to maximize due inappropriate nanostructural design. Herein, a nano-emulsion induced polymerization self-assembly strategy is employed prepare hierarchical meso-/microporous N/S co-doped carbon nanocage with atomically dispersed FeN4 (denoted as Meso/Micro-FeNSC). In situ scanning electrochemical microscopy technology reveals available for Meso/Micro-FeNSC reach 3.57 × 1014 cm-2 , representing more than threefold improvement compared micropore-dominant Micro-FeNSC counterpart (1.07 ). Additionally, turnover frequency also improved 0.69 from 0.50 e- site-1 s-1 Micro-FeNSC. These properties motivate efficient electroreduction electrocatalyst, in terms outstanding half-wave potential (0.91 V), remarkable kinetic mass specific activity (68.65 A g-1 ), excellent robustness. The assembled Zn-air batteries deliver high peak power (264.34 mW large capacity (814.09 mA h long cycle life (>200 h). This work sheds lights on quantifying site significance maximum rational design advanced catalysts.

Language: Английский

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Electronic Modulation of Metal–Organic Frameworks by Interfacial Bridging for Efficient pH‐Universal Hydrogen Evolution

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 33(1)

Published: Oct. 26, 2022

Abstract Designing well‐defined interfacial chemical bond bridges is an effective strategy to optimize the catalytic activity of metal–organic frameworks (MOFs), but it remains challenging. Herein, a facile in situ growth reported for synthesis tightly connected 2D/2D heterostructures by coupling MXene with CoBDC nanosheets. The multifunctional nanosheets high conductivity and ideal hydrophilicity as bridging carriers can ensure structural stability sufficient exposure active sites. Moreover, Co–O–Ti formed at interface effectively triggers charge transfer modulates electronic structure Co‐active site, which enhances reaction kinetics. As result, optimized CoBDC/MXene exhibits superior hydrogen evolution (HER) low overpotentials 29, 41, 76 mV 10 mA cm −2 alkaline, acidic, neutral electrolytes, respectively, comparable commercial Pt/C. Theoretical calculation demonstrates that bridging‐induced electron redistribution optimizes free energy water dissociation adsorption, resulting improved evolution. This study not only provides novel electrocatalyst efficient HER all pH conditions also opens up new avenue designing highly systems.

Language: Английский

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