Millisecond activity modulation of atomically-dispersed Fe–N–C catalysts

Energy storage materials, Journal Year: 2024, Volume and Issue: 69, P. 103421 - 103421

Published: April 28, 2024

Language: Английский

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Experimentally validating sabatier plot by molecular level microenvironment customization for oxygen electroreduction

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: July 19, 2024

Abstract Microenvironmental modifications on metal sites are crucial to tune oxygen reduction catalytic behavior and decrypt intrinsic mechanism, whereas the stochastic properties of traditional pyrolyzed single-atom catalysts induce vague recognition structure-reactivity relations. Herein, we report a theoretical descriptor relying binding energies adsorbates directly associating derived Sabatier volcano plot with calculated overpotential forecast efficiency cobalt porphyrin. This instructs that electron-withdrawing substituents mitigate over-strong *OH intermediate adsorption by virtue decreased proportion electrons in bonding orbital. To experimentally validate this speculation, implement secondary sphere microenvironment customization strategy porphyrin-based polymer nanocomposite analogs. Systematic X-ray spectroscopic situ electrochemical characterizations capture pronounced accessible active site density fast interfacial/outward charge migration kinetics contributions for optimal carboxyl group-substituted catalyst. work offers ample strategies designing well-managed under guidance map.

Language: Английский

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Pyridinic-N Regulated Electron Injection to Modulate *OH Adsorption at Fe–N–C Sites for an Efficient Oxygen Reduction Reaction

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: 16(32), P. 42352 - 42362

Published: July 31, 2024

To enhance the efficiency of oxygen reduction reaction (ORR) catalysts, precise control over adsorption/desorption energy barriers intermediates at atomically dispersed Fe–N–C sites is essential yet challenging. Addressing this, we employed a pyrolysis approach using nitrogen-containing polymer to fabricate Fe single-atom (SA) catalysts embedded in pyridinic-N enriched carbon matrix. This synthesis strategy yielded SAs that demonstrated superior electrochemical ORR performance, evidenced by an impressive half-wave potential 0.941 V and high limiting current density 5.72 mA/cm2. Moreover, when applied homemade Zn–air batteries, this premier catalyst exhibited exceptional specific capacity (720 mAh/gZn), peak power (253 mW/cm2), notable long-term stability. Theoretical insights revealed increased content facilitated efficient electron transfer from N atoms active sites, thus fine-tuning d-band center effectively controlling adsorption barrier *OH species. These mechanisms synergistically improve performance. Crucially, fabrication method shows promise for adaptation other transition metal-based SAs, including Co, Ni, Cu, potentially establishing versatile route developing systems future applications.

Language: Английский

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Anchoring covalent organic polymers on supports with tunable functional groups boosting the oxygen reduction performance under pH-universal conditions

Journal of Colloid and Interface Science, Journal Year: 2024, Volume and Issue: 661, P. 923 - 929

Published: Feb. 3, 2024

Language: Английский

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Two‐Dimensional Metallophthalocyanine Nanomaterials for Electrocatalytic Energy Conversion

Energy & environment materials, Journal Year: 2024, Volume and Issue: 7(4)

Published: Jan. 31, 2024

Growing energy demand drives the rapid development of clean and reliable sources. In past years, exploration novel materials with considerable efficiency durability has drawn attention in area electrochemical conversion. Transition metal macrocyclic metallophthalocyanines (MPcs)‐based catalysts a peculiar 2D constitution have emerged promising future account their highly structural tailorability molecular functionality which greatly extend functionalities as electrocatalytic for This review summarizes systematic engineering synthesis MPcs analogs detail, mostly pays to frontier research MPc‐based high‐performance toward different processes concerning hydrogen, oxygen, water, carbon dioxide, nitrogen, particular focus on discussing interrelationship between activity component/structure, well functional applications MPcs. Finally, we give gaps that need be addressed after much thought.

Language: Английский

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Universal Sublimation Strategy to Stabilize Single-Metal Sites on Flexible Single-Wall Carbon-Nanotube Films with Strain-Enhanced Activities for Zinc–Air Batteries and Water Splitting

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: 16(13), P. 16164 - 16174

Published: March 21, 2024

Single-metal-site catalysts have recently aroused extensive research in electrochemical energy fields such as zinc-air batteries and water splitting, but their preparation is still a huge challenge, especially flexible catalyst films. Herein, we propose sublimation strategy which metal phthalocyanine molecules with defined isolated metal-N4 sites are gasified by then deposited on single-wall carbon nanotube (SWCNT) films means of π–π coupling interactions. Specifically, iron anchored the SWCNT film prepared was directly used to boost cathodic oxygen reduction reaction battery, showing high peak power density 247 mW cm–2. Nickel cobalt were, respectively, stabilized anodic electrocatalysts for low potential 1.655 V at 10 mA In situ Raman spectra theoretical studies demonstrate that highly efficient activities originate from strain-induced SWCNTs. This work provides universal method single-metal-site innovative insights electrocatalytic mechanisms.

Language: Английский

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Investigating the Role of Fe‐Pyrrolic N4 Configuration in the Oxygen Reduction Reaction via Covalently Bound Porphyrin Functionalized Carbon Nanotubes

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 34(16)

Published: Dec. 31, 2023

Abstract Atomically dispersed iron–nitrogen–carbon catalysts are promised, low‐cost, and high‐performance electrocatalysts for the Oxygen Reduction Reaction (ORR) in fuel cells. However, most Fe–N–C materials produced via pyrolysis at a high temperature it is difficult to characterise precise Fe–N configurations. This can lead confusion surrounding best chemical coordination environment Fe understanding subsequent ORR mechanisms. In this work, porphyrin used produce specific environment, therefore allowing role activity of be studied. Carbon nanotubes (CNTs) covalently functionalized with iron 5,10,15,20‐triphenylporphyrin (FeTPP) motifs aryl diazonium methodology, enabling exact only Fe‐Pyrrolic N4 configuration FeTPP studied better understood. Upon covalent functionalization, electrochemical active site density 1.12 × 10 15 sites cm −2 , approximately six‐fold more than that noncovalently samples 12.7% site. The heightened superior utilization (12.7%) favorable 4‐electron pathway ORR. Furthermore, preliminary discussion regarding selectivity initiated.

Language: Английский

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Iron, Cobalt, and Nickel Phthalocyanine Tri-Doped Electrospun Carbon Nanofibre-Based Catalyst for Rechargeable Zinc–Air Battery Air Electrode

Materials, Journal Year: 2023, Volume and Issue: 16(13), P. 4626 - 4626

Published: June 27, 2023

The goal of achieving the large-scale production zero-emission vehicles by 2035 will create high expectations for electric vehicle (EV) development and availability. Currently, a major problem is lack suitable batteries battery materials in large quantities. rechargeable zinc-air (RZAB) promising energy-storage technology EVs due to environmental friendliness low cost. Herein, iron, cobalt, nickel phthalocyanine tri-doped electrospun carbon nanofibre-based (FeCoNi-CNF) catalyst material presented as an affordable alternative Pt-group metal (PGM)-based catalyst. FeCoNi-CNF-coated glassy electrode showed oxygen reduction reaction/oxygen evolution reaction reversibility 0.89 V 0.1 M KOH solution. In RZAB, maximum discharge power density (Pmax) 120 mW cm-2 was obtained with FeCoNi-CNF, which 86% Pmax measured PGM-based Furthermore, during RZAB charge-discharge cycling, FeCoNi-CNF air found be superior commercial PGM electrocatalyst terms operational durability at least two times higher total life-time.

Language: Английский

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Donor–acceptor iron phthalocyanine-based hyper-crosslinked polymers with a modulated electronic structure for efficient oxygen reduction reaction in aluminum–air batteries

Journal of Materials Chemistry A, Journal Year: 2024, Volume and Issue: 12(23), P. 13800 - 13809

Published: Jan. 1, 2024

Poly-FePc-based HCPs with TTF modification are constructed and applied as ORR catalyst for Al–air batteries. The donor–acceptor structure was incorporated into poly-FePc-HCP to achieve structural electronic regulation.

Language: Английский

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Engineering the Catalyst Layer of a Pyrolysis-Free Nonprecious Metal Catalyst for Enhancing Anion-Exchange Membrane Fuel Cells

ACS Applied Energy Materials, Journal Year: 2025, Volume and Issue: 8(1), P. 552 - 558

Published: Jan. 2, 2025

Nonprecious metal catalysts (NPMCs) for oxygen reduction reaction (ORR) in an alkaline environment provide a prominent advantage the development of low-cost anion-exchange membrane fuel cells (AEMFCs). However, synthesis highly active NPMCs typically involves high-temperature pyrolysis, which increases time consumption and energy input, especially during scale-up process. Herein, we report mild graphene aerogel-based pyrolysis-free NPMC (FePc-GA) AEMFCs. The physical characterizations demonstrate strong chemical coupling between aerogel FePc FePc-GA. electrochemical evaluation evidences that this FePc-GA shows excellent ORR activity with half-wave potential 0.92 V half-cell conditions. In addition, by regulation ink formulation, AEMFC reaches 16 times higher power density using NPMC. This work highlights feasibility catalyst layer engineering can significantly advance application cost-effective, sustainable

Language: Английский

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