Heteroatom‐Driven Coordination Fields Altering Single Cerium Atom Sites for Efficient Oxygen Reduction Reaction

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(28)

Published: April 4, 2023

For current single-atom catalysts (SACs), modulating the coordination environments of rare-earth (RE) single atoms with complex electronic orbital and flexible chemical states is still limited. Herein, cerium (Ce) SAs supported on a P, S, N co-doped hollow carbon substrate (Ce SAs/PSNC) for oxygen reduction reaction (ORR) are reported. The as-prepared Ce SAs/PSNC possesses half-wave potential 0.90 V, turnover frequency value 52.2 s

Language: Английский

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Reconstruction of Highly Dense Cu−N₄Active Sites in Electrocatalytic Oxygen Reduction Characterized by Operando Synchrotron Radiation

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(40)

Published: Aug. 22, 2022

The emerging star of single atomic site (SAS) catalyst has been regarded as the most promising Pt-substituted electrocatalyst for oxygen reduction reaction (ORR) in anion-exchange membrane fuel cells (AEMFCs). However, metal loading SAS directly affects whole device performance. Herein, we report a dual nitrogen source coordinated strategy to realize high dense Cu-N4 with 5.61 wt% supported on 3D N-doped carbon nanotubes/graphene structure wherein simultaneously performs superior ORR activity and stability alkaline media. When applied H2 /O2 AEMFC, it could reach an open-circuit voltage 0.90 V peak power density 324 mW cm-2 . Operando synchrotron radiation analyses identify reconstruction from initial /Cu-nanoclusters (NC) subsequent Cu-N3 /Cu-NC under working conditions, which gradually regulate d-band center central balance Gibbs free energy *OOH *O intermediates, benefiting activity.

Language: Английский

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Tuning the Coordination Environment of Carbon‐Based Single‐Atom Catalysts via Doping with Multiple Heteroatoms and Their Applications in Electrocatalysis

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(38)

Published: Feb. 13, 2023

Abstract Carbon‐based single‐atom catalysts (SACs) are considered to be a perfect platform for studying the structure–activity relationship of different reactions due adjustability their coordination environment. Multi‐heteroatom doping has been demonstrated as an effective strategy tuning environment carbon‐based SACs and enhancing catalytic performance in electrochemical reactions. Herein, recently developed strategies multi‐heteroatom doping, focusing on regulation active sites by heteroatoms shells, summarized. In addition, correlation between activity investigated through representative experiments theoretical calculations various Finally, concerning certain shortcomings current multi‐heteroatoms, some suggestions put forward promote development field electrocatalysis.

Language: Английский

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Dual‐Sites Coordination Engineering of Single Atom Catalysts for Full‐Temperature Adaptive Flexible Ultralong‐Life Solid‐State Zn−Air Batteries

Advanced Functional Materials, Journal Year: 2022, Volume and Issue: 33(8)

Published: Dec. 14, 2022

Abstract High‐performance rechargeable Zn‐air batteries with long‐life stability are desirable for power applications in electric vehicles. The key component of the is bifunctional oxygen electrocatalyst, however, designing a electrocatalyst high intrinsic reversibility and durability challenge. Through density functional theory calculations, it found that catalytic activity originated from electronic geometric coordination structures synergistic effect Fe Co dual‐sites metal‐N 4 environment, assisting stronger hybridization orbitals between ( dxz, dz 2 ) OO* px, pz ), thus making O active ability site. These findings enable to development fancy dual single‐atom catalyst comprising adjacent FeN CoN sites on N‐doped carbon matrix (FeCo‐NC). FeCo‐NC exhibits extraordinary activities reduction evolution reaction (ORR/OER), which displays half‐wave potential (0.893 V) ORR, low overpotential (343 mV) at 10 mA cm −2 OER. assembled air‐electrode works well flexible solid‐state battery specific capacity 747.0 mAh g −1 , long‐time more than 400 h (30 °C), also superior performance extreme temperatures (−30 °C–60 °C).

Language: Английский

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Altering the spin state of Fe-N-C through ligand field modulation of single-atom sites boosts the oxygen reduction reaction

Nano Energy, Journal Year: 2022, Volume and Issue: 105, P. 108020 - 108020

Published: Nov. 21, 2022

Language: Английский

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A Fe Single Atom Seed‐Mediated Strategy Toward Fe₃C/FeNC Catalysts with Outstanding Bifunctional ORR/OER Activities

Advanced Science, Journal Year: 2023, Volume and Issue: 10(22)

Published: May 31, 2023

The discovery of low-cost and high-performance bifunctional oxygen electrocatalysts is vital to the future commercialization rechargeable zinc-air batteries (ZABs). Herein, a Fe single atom seed-mediated strategy reported for fabrication Fe3 C species closely surrounded by FeN4 C active sites with strong electronic interactions built between them more importantly, creating optimized coordination environment, via subtly adjusting their ratio, favorable adsorption energies intermediates formed during reduction reaction (ORR) evolution (OER). Concretely, voltage difference (ΔE) ORR half-wave OER potential at current density 10 mA cm-2 compositionally-optimized FeNC/Fe3 C-op electrocatalyst only 0.668 V, endowing itself one best OER/ORR benchmarks. As demo, ZABs assembled as air cathode deliver remarkable specific capacity (818.1 mAh gZn-1 ) power (1013.9 mWh ), along excellent long-term durability (>450 h). This work extends methodology modulate activity atomic site, undoubtedly inspiring wide explorations on precise design electrocatalysts.

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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Progress in metal-organic-framework-based single-atom catalysts for environmental remediation

Coordination Chemistry Reviews, Journal Year: 2022, Volume and Issue: 474, P. 214855 - 214855

Published: Oct. 4, 2022

Language: Английский

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Hetero‐Anionic Structure Activated CoS Bonds Promote Oxygen Electrocatalytic Activity for High‐Efficiency Zinc–Air Batteries

Advanced Materials, Journal Year: 2023, Volume and Issue: 35(36)

Published: May 18, 2023

Abstract The electronic structure of transition metal complexes can be modulated by replacing partial ion to obtain tuned intrinsic oxygen reduction reaction (ORR) or evolution (OER) electrocatalytic activity. However, the anion‐modulated ORR activity is still unsatisfactory, and construction hetero‐anionic remains challenging. Herein, an atomic doping strategy presented prepare CuCo 2 O 4‐x S x /NC‐2 (CCSO/NC‐2) as electrocatalysts, structrual characterization results favorably demonstrate substitution atoms for in CCSO/NC‐2, which shows excellent catalytic performance durability OER 0.1 m KOH. In addition, catalyst assembled Zinc–air battery with open circuit potential 1.43 V maintains after 300 h cyclic stability. Theoretical calculations differential charges illustrate that optimizes kinetics promotes electron redistribution. superior CCSO/NC‐2 catalysis mainly due its unique modulation main body. introduction CoO covalency constructs a fast transport channel, thus optimizing adsorption degree active site Co intermediates.

Language: Английский

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Single-atom CoN4 sites with elongated bonding induced by phosphorus doping for efficient H2O2 electrosynthesis

Applied Catalysis B Environment and Energy, Journal Year: 2022, Volume and Issue: 324, P. 122267 - 122267

Published: Dec. 5, 2022

Language: Английский

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