Understanding the structure-performance relationship of active sites at atomic scale

Nano Research, Journal Year: 2022, Volume and Issue: 15(8), P. 6888 - 6923

Published: June 14, 2022

Language: Английский

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Theory‐Guided Regulation of FeN₄Spin State by Neighboring Cu Atoms for Enhanced Oxygen Reduction Electrocatalysis in Flexible Metal–Air Batteries

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(27)

Published: April 25, 2022

Iron, nitrogen-codoped carbon (Fe-N-C) nanocomposites have emerged as viable electrocatalysts for the oxygen reduction reaction (ORR) due to formation of FeNx Cy coordination moieties. In this study, results from first-principles calculations show a nearly linear correlation energy barriers key steps with Fe magnetic moment. Experimentally, when single Cu sites are incorporated into Fe-N-C aerogels (denoted NCAG/Fe-Cu), centers exhibit reduced moment and markedly enhanced ORR activity within wide pH range 0-14. With NCAG/Fe-Cu used cathode catalyst in neutral/quasi-solid aluminum-air alkaline/quasi-solid zinc-air battery, both achieve remarkable performance an ultrahigh open-circuit voltage 2.00 1.51 V, large power density 130 186 mW cm-2 , good mechanical flexibility, all better than those commercial Pt/C or Pt/C-RuO2 catalysts at cathode.

Language: Английский

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Atomically precise electrocatalysts for oxygen reduction reaction

Chem, Journal Year: 2023, Volume and Issue: 9(2), P. 280 - 342

Published: Feb. 1, 2023

Language: Английский

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Simultaneously Integrate Iron Single Atom and Nanocluster Triggered Tandem Effect for Boosting Oxygen Electroreduction

Small, Journal Year: 2022, Volume and Issue: 18(15)

Published: Feb. 26, 2022

Abstract Atomically nitrogen‐coordinated iron atoms on carbon (FeNC) catalysts are emerging as attractive materials to substitute precious‐metal‐based for the oxygen reduction reaction (ORR). However, FeNC usually suffers from unsatisfactory performance due symmetrical charge distribution around site. Elaborately regulating microenvironment of central Fe atom can substantially improve catalytic activity FeNC, which remains challenging. Herein, N/S co‐doped porous carbons rationally prepared and verified with rich Fe‐active sites, including atomically dispersed FeN 4 nanoclusters (FeSA‐FeNC@NSC), according systematically synchrotron X‐ray absorption spectroscopy analysis. Theoretical calculation verifies that contiguous S break symmetric electronic structure synergistically optimize 3 d orbitals centers, thus accelerating OO bond cleavage in OOH* improving ORR activity. The FeSA‐Fe NC @NSC delivers an impressive half‐wave‐potential 0.90 V, exceeds state‐of‐the‐art Pt/C (0.87 V). Furthermore, @NSC‐based Zn‐air batteries deliver excellent power densities 259.88 55.86 mW cm –2 liquid all‐solid‐state flexible configurations, respectively. This work presents effective strategy modulate single atomic centers boost single‐atom by tandem effect.

Language: Английский

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Tailoring Oxygen Reduction Reaction Kinetics of Fe−N−C Catalyst via Spin Manipulation for Efficient Zinc–Air Batteries

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(25)

Published: April 9, 2024

The interaction between oxygen species and metal sites of various orbitals exhibits intimate correlation with the reduction reaction (ORR) kinetics. Herein, a new approach for boosting inherent ORR activity atomically dispersed Fe-N-C matrix is represented by implanting Fe atomic clusters nearby. as-prepared catalyst delivers excellent half-wave potentials 0.78 0.90 V in acidic alkaline solutions, respectively. decent can also be validated from high-performance rechargeable Zn-air battery. experiments density functional theory calculations reveal that electron spin-state monodispersed active transferred low spin (LS, t

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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Bifunctional Single Atom Catalysts for Rechargeable Zinc–Air Batteries: From Dynamic Mechanism to Rational Design

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

Published: June 7, 2023

Ever-growing demands for rechargeable zinc-air batteries (ZABs) call efficient bifunctional electrocatalysts. Among various electrocatalysts, single atom catalysts (SACs) have received increasing attention due to the merits of high utilization, structural tunability, and remarkable activity. Rational design SACs relies heavily on an in-depth understanding reaction mechanisms, especially dynamic evolution under electrochemical conditions. This requires a systematic study in mechanisms replace current trial error modes. Herein, fundamental oxygen reduction is first presented combining situ and/or operando characterizations theoretical calculations. By highlighting structure-performance relationships, rational regulation strategies are particularly proposed facilitate SACs. Furthermore, future perspectives challenges discussed. review provides thorough SACs, which expected pave avenue exploring optimum effective ZABs.

Language: Английский

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Co(CN)3 catalysts with well-defined coordination structure for the oxygen reduction reaction

Nature Catalysis, Journal Year: 2023, Volume and Issue: 6(12), P. 1164 - 1173

Published: Nov. 16, 2023

Language: Английский

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Vacancy Defects Inductive Effect of Asymmetrically Coordinated Single‐Atom Fe─N₃S₁ Active Sites for Robust Electrocatalytic Oxygen Reduction with High Turnover Frequency and Mass Activity

Advanced Materials, Journal Year: 2023, Volume and Issue: 36(11)

Published: Dec. 16, 2023

Abstract The development of facile, efficient synthesis method to construct low‐cost and high‐performance single‐atom catalysts (SACs) for oxygen reduction reaction (ORR) is extremely important, yet still challenging. Herein, an atomically dispersed N, S co‐doped carbon with abundant vacancy defects (NSC‐vd) anchored Fe single atoms (SAs) reported a inductive effect proposed promoting electrocatalytic ORR. optimized catalyst featured stable Fe─N 3 1 active sites exhibits excellent ORR activity high turnover frequency mass activity. In situ Raman, attenuated total reflectance surface enhanced infrared absorption spectroscopy reveal the exhibit different kinetic mechanisms in acidic alkaline solutions. Operando X‐ray spectra SAs/NSC‐vd electrolyte closely related coordination structure. Theoretical calculation reveals upshifted d band center facilitates adsorption O 2 accelerates kinetics process *OH reduction. around balance OOH* formation reduction, thus synergetically process.

Language: Английский

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Steering Local Electronic Configuration of Fe–N–C‐Based Coupling Catalysts via Ligand Engineering for Efficient Oxygen Electroreduction

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

Published: Nov. 14, 2022

Abstract Fe–N–C materials are prospective candidates to displace platinum‐group‐based oxygen reduction reaction (ORR) catalysts, but their application is still impeded by the conundrums of unsatisfactory activity and stability. Herein, a feasible strategy ligand engineering metal‐organic framework proposed steer local electronic configuration Fe–N–C‐based coupling catalysts incorporating engineered sulfur functionalities. The obtained with rich Fe‐N 4 sites FeS nanoparticles embedded on N/S‐doped carbon (denoted as FeS/FeNSC). In this unique structure, oxidized synergistically induce electron redistribution modulate sites, contributing substantially accelerated kinetics improved activity. Consequently, optimized FeS/FeNSC catalyst displays outstanding ORR performance half‐wave potential 0.91 V, better four pathway selectivity, lower H 2 O yield, superior long‐term As proof‐of‐concept, zinc‐air batteries based deliver high capacity 807.54 mA h g −1 , remarkable peak power density 256.06 mW cm −2 cycling stability over 600 at 20 . This study delivers an efficacious approach manipulate toward elevated catalytic for various energy conversion/storage devices.

Language: Английский

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