Engineering the Electronic Structure of Single‐Atom Iron Sites with Boosted Oxygen Bifunctional Activity for Zinc–Air Batteries

Advanced Materials, Journal Year: 2022, Volume and Issue: 35(9)

Published: Dec. 19, 2022

Abstract Rechargeable zinc–air batteries typically require efficient, durable, and inexpensive bifunctional electrocatalysts to support oxygen reduction/evolution reactions (ORR/OER). However, sluggish kinetics mass transportation challenges must be addressed if the performance of these catalysts is enhanced. Herein, a strategy fabricate catalyst comprising atomically dispersed iron atoms supported on mesoporous nitrogen‐doped carbon (Fe SAs/NC) with accessible metal sites optimized electronic metal–support interactions developed. Both experimental results theoretical calculations reveal that engineered structures active can regulate charge distribution Fe centers optimize adsorption/desorption oxygenated intermediates. The SAs/NC containing 1 N 4 O achieves remarkable ORR activity over entire pH range, half‐wave potentials 0.93, 0.83, 0.75 V (vs reversible hydrogen electrode) in alkaline, acidic, neutral electrolytes, respectively. In addition, it demonstrates promising low overpotential 320 mV at 10 mA cm −2 for OER alkaline conditions. battery assembled exhibits superior than Pt/C+RuO 2 counterpart terms peak power density, specific capacity, cycling stability. These findings demonstrate importance structure engineering directing catalytic activity.

Language: Английский

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Geometric and Electronic Engineering of Atomically Dispersed Copper‐Cobalt Diatomic Sites for Synergistic Promotion of Bifunctional Oxygen Electrocatalysis in Zinc–Air Batteries

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(25)

Published: April 11, 2023

The development of rechargeable zinc-air batteries is heavily dependent on bifunctional oxygen electrocatalysts to offer exceptional reduction/evolution reaction (ORR/OER) activities. However, the design such with high activity and durability challenging. Herein, a strategy proposed create an electrocatalyst comprised copper-cobalt diatomic sites highly porous nitrogen-doped carbon matrix (Cu-Co/NC) abundantly accessible metal optimal geometric electronic structures. Experimental findings theoretical calculations demonstrate that synergistic effect Cu-Co dual-metal metal-N4 coordination induce asymmetric charge distributions moderate adsorption/desorption behavior intermediates. This exhibits extraordinary electrocatalytic activities in alkaline media, half-wave potential 0.92 V for ORR low overpotential 335 mV at 10 mA cm-2 OER. In addition, it demonstrates acidic (0.85 V) neutral (0.74 media. When applied battery, achieves operational performance outstanding (510 h), ranking as one most efficient reported date. work importance engineering isolated boosting electrochemical energy devices.

Language: Английский

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The strain induced synergistic catalysis of FeN4 and MnN3 dual-site catalysts for oxygen reduction in proton- /anion- exchange membrane fuel cells

Applied Catalysis B Environment and Energy, Journal Year: 2022, Volume and Issue: 317, P. 121770 - 121770

Published: July 20, 2022

Language: Английский

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Developing a class of dual atom materials for multifunctional catalytic reactions

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Nov. 8, 2023

Dual atom catalysts, bridging single and metal/alloy nanoparticle offer more opportunities to enhance the kinetics multifunctional performance of oxygen reduction/evolution hydrogen evolution reactions. However, rational design efficient dual catalysts remains a blind area is challenging. In this study, we achieved controllable regulation from Co nanoparticles CoN4 atoms Co2N5 using an atomization sintering strategy via N-stripping thermal-migrating process. More importantly, could be extended fabrication 22 distinct catalysts. particular, with tailored spin states achieve ideally balanced adsorption/desorption intermediates, thus realizing superior activity. addition, it endows Zn-air batteries long-term stability for 800 h, allows water splitting continuously operate 1000 can enable solar-powered systems uninterrupted large-scale production throughout day night. This universal scalable provides controlled in energy conversion technologies.

Language: Английский

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Modulation of Ligand Fields in a Single-Atom Site by the Molten Salt Strategy for Enhanced Oxygen Bifunctional Activity for Zinc-Air Batteries

ACS Nano, Journal Year: 2022, Volume and Issue: 16(8), P. 11944 - 11956

Published: July 26, 2022

Achieving full utilization of active sites and optimization the electronic structure metal centers is key to improving intrinsic activity single-atom catalysts (SACs) but still remains a challenge date. Herein, versatile molten salt-assisted pyrolysis strategy was developed construct ultrathin, porous carbon nanosheets supported Co SACs. Molten salts are capable inducing formation graphene-like carbon, which facilitates exposure center simultaneously endows SACs with abundant defective Co-N4 configurations. The reported deliver an excellent bifunctional good stability for oxygen reduction reaction (ORR) evolution (OER). Moreover, metal-air batteries (MABs) assembled as air electrode also performance high power densities 160 mW·cm-2, large capacities 760 mAh·g-1, superior long-term charge/discharge stability, outperforming those commercial Pt/C+RuO2. DFT theoretical calculation results show that defects in second coordination shell (CS) promote desorption OH* intermediate ORR facilitate deprotonation OER, can serve favorable site catalysts. Our work provides efficient preparation fully exposed optimized structures.

Language: Английский

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Review on the Degradation Mechanisms of Metal-N-C Catalysts for the Oxygen Reduction Reaction in Acid Electrolyte: Current Understanding and Mitigation Approaches

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(15), P. 9265 - 9326

Published: July 11, 2023

One bottleneck hampering the widespread use of fuel cell vehicles, in particular proton exchange membrane cells (PEMFCs), is high cost cathode where oxygen reduction reaction (ORR) occurs, due to current need precious metals catalyze this reaction. Electrochemists tackle issue short/medium term by developing catalysts with improved utilization or efficiency platinum, and longer term, based on Earth-abundant elements. Considerable progress has been achieved initial performance Metal-nitrogen-carbon (Metal-N-C) for ORR, especially Fe-N-C materials. However, until now, cannot be maintained a sufficiently long time an operating PEMFC. The identification mitigation degradation mechanisms Metal-N-C electrocatalysts acidic environment PEMFCs therefore become important research topic. Here, we review recent advances understanding electrocatalysts, including recently identified importance combined electrochemical potential. Results obtained liquid electrolyte PEMFC device are discussed, as well insights gained from situ operando techniques. We also approaches that scientific community hitherto investigated overcome durability issues electrocatalysts.

Language: Английский

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Dual-site segmentally synergistic catalysis mechanism: boosting CoFeSx nanocluster for sustainable water oxidation

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

Published: Feb. 26, 2024

Abstract Efficient oxygen evolution reaction electrocatalysts are essential for sustainable clean energy conversion. However, catalytic materials followed the conventional adsorbate mechanism (AEM) with inherent scaling relationship between key intermediates *OOH and *OH, or lattice-oxygen-mediated (LOM) possible lattice migration structural reconstruction, which not favorable to balance high activity stability. Herein, we propose an unconventional Co-Fe dual-site segmentally synergistic (DSSM) single-domain ferromagnetic catalyst CoFeS x nanoclusters on carbon nanotubes (CNT) (CFS-ACs/CNT), can effectively break without sacrificing Co 3+ (L.S, t 2g 6 e g 0 ) supplies strongest OH* adsorption energy, while Fe (M.S, 4 1 exposes strong O* adsorption. These dual-sites synergistically produce of Co-O-O-Fe intermediates, thereby accelerating release triplet-state ( ↑ O = ). As predicted, prepared CFS-ACs/CNT exhibits less overpotential than that commercial IrO 2 , as well approximately 633 h stability significant potential loss.

Language: Английский

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Recent Advances in Non‐Precious Metal Single‐Atom Electrocatalysts for Oxygen Reduction Reaction in Low‐Temperature Polymer‐Electrolyte Fuel Cells

ChemCatChem, Journal Year: 2023, Volume and Issue: 15(22)

Published: Oct. 9, 2023

Abstract Fuel cells have emerged as a promising clean electrochemical energy technology with great potential in various sectors, including transportation and power generation. However, the high cost scarcity of noble metals currently used to synthesise electrocatalysts for low‐temperature fuel has hindered their widespread commercialisation. In recent decades, development non‐precious metal cathodic oxygen reduction reaction (ORR) gained significant attention. Among those, atomically dispersed active sites, referred single‐atom catalysts (SACs), are gaining more interest. Nanocarbon materials containing single transition atoms coordinated nitrogen ORR both acidic alkaline conditions thus promise be utilised cathode cells. This review article provides an overview advancements utilisation metal‐based SACs proton exchange membrane (PEMFCs) anion (AEMFCs). We highlight main strategies synthetic approaches tailoring properties enhance activity durability. Based on already achieved results, it is evident that indeed could suitable

Language: Английский

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Active site engineering toward atomically dispersed M−N−C catalysts for oxygen reduction reaction

Coordination Chemistry Reviews, Journal Year: 2023, Volume and Issue: 495, P. 215400 - 215400

Published: Aug. 21, 2023

Language: Английский

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Single-Atom-Based Oxygen Reduction Reaction Catalysts for Proton Exchange Membrane Fuel Cells: Progress and Perspective

ACS Nano, Journal Year: 2023, Volume and Issue: 17(20), P. 19514 - 19525

Published: Oct. 9, 2023

Single-atom catalysts (SACs) are regarded as promising non-noble-metal alternatives for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells due to their high atom utilization efficiency and excellent catalytic properties. However, insufficient long-term stability issues of SACs under working conditions seriously hinder practical application. In this perspective, recent progress with optimized ORR activity is first reviewed. Then, possible degradation mechanisms process effective strategies improving durability summarized. Finally, some challenges opportunities proposed develop stable single-atom-based electrocatalysts future.

Language: Английский

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