Nitrogen-doped carbon achieving the construction of high-loading Pt catalyst and enhancement of fuel cells performance

International Journal of Hydrogen Energy, Journal Year: 2025, Volume and Issue: 103, P. 205 - 212

Published: Jan. 18, 2025

Language: Английский

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Fresh perspectives and insights into the challenges and opportunities in the emerging high-entropy electrocatalysts

Coordination Chemistry Reviews, Journal Year: 2025, Volume and Issue: 531, P. 216496 - 216496

Published: Feb. 16, 2025

Language: Английский

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Engineering Asymmetric Electronic Structure of Co─N─C Single‐Atomic Sites Toward Excellent Electrochemical H₂O₂ Production and Biomass Upgrading

Angewandte Chemie International Edition, Journal Year: 2025, Volume and Issue: unknown

Published: March 11, 2025

Abstract To advance electrochemical H 2 O production and unravel catalytic mechanisms, the precise structural coordination of single‐atomic M‐N‐C electrocatalysts is urgently required. Herein, Co─N 5 site with an asymmetric electronic configuration constructed to boost two‐electron oxygen reduction reaction (2e − ORR) compared symmetric 4 , effectively overcoming trade‐off between activity selectivity in production. Both experimental theoretical analyses demonstrate that breaking symmetry sites promotes activation molecules moderates adsorption key *OOH intermediate by disrupting linear scaling relationship for intermediates adsorption. This modulation enables efficient H₂O₂ its effective retention subsequent applications. As a proof concept, achieves rate as high 16.1 mol g cat −1 h flow cell, outperforming most recently reported counterparts. Furthermore, coupling 2e ORR oxidation cellulose‐derived carbohydrates accomplishes formic acid yields (84.1% from glucose 62.0%–92.1% other substrates), underpinning sustainable electro‐refinery biomass valorization at ambient conditions. By elucidating intrinsic 2e⁻ asymmetry sites, this work paves way high‐performance electrosynthesis.

Language: Английский

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Unraveling Dynamic Structural Evolution of Single Atom Catalyst via In Situ Surface-Enhanced Infrared Absorption Spectroscopy

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: March 7, 2025

Metal–nitrogen-carbon (M–N-C) single-atom catalysts (SACs) have been widely applied in catalyzing electrochemical redox reactions. However, their long-term catalytic stabilities greatly limit practical applications. This work investigates the dynamic evolution of two model Cu–N–C SACs with different Cu–N coordinations, namely Cu1/Npyri-C and Cu1/Npyrr-C, CO reduction reaction (CORR), based on a collection situ characterizations including attenuated total reflectance surface-enhanced infrared absorption spectroscopy, X-ray quasi-in electron paramagnetic resonance spectroscopy ultraviolet–visible complemented by theoretical calculations. Our findings reveal that Cu nanoparticle formation rate over Cu1/Npyrr-C is more than 6 times higher during CORR. Quasi-in UV–vis measurements demonstrate hydrogen radicals can be produced CORR, which will attack bonds SACs, causing leaching Cu2+ followed subsequent to form nanoparticles. Kinetic calculations show displays better stability resulting from stronger Cu–Npyri bonds. study deepens understanding deactivation mechanism reactions provides guidance for design next-generation enhanced durability.

Language: Английский

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Intramolecular electron transfer for optimized coordination environment in bimetallic molecular electrocatalysts for flexible zinc-air battery applications

Journal of Energy Storage, Journal Year: 2025, Volume and Issue: 118, P. 116335 - 116335

Published: March 21, 2025

Language: Английский

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Densely accessible Fe/Co–N_x dual-atom site coupled core–shell Co₃Fe₇@C as an efficient bifunctional oxygen electrocatalyst for rechargeable zinc–air batteries

Journal of Materials Chemistry A, Journal Year: 2024, Volume and Issue: 12(27), P. 16863 - 16876

Published: Jan. 1, 2024

The symmetric electronic structure of an Fe single-atom site catalyst was effectively regulated by incorporating Co–N x sites and core–shell Co 3 7 @C nanoparticles, resulting in high performance towards the ORR Zn–air batteries.

Language: Английский

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Fe Single Atoms Encased in Nanoscale Zif-8 Dodecahedra for Oxygen Reduction and Flexible Zinc–Air Batteries

ACS Applied Nano Materials, Journal Year: 2024, Volume and Issue: 7(11), P. 13547 - 13556

Published: May 22, 2024

The development of efficient and facile nonprecious metal catalysts for the oxygen reduction reaction (ORR) holds great significance. Among these, single-atomic metal–nitrogen–carbon (M–N–C) are emerging candidates due to their high activity prolonged lifespan. However, traditional preparation M–N–C suffers from thermal aggregation low space–time yield, limiting application in industry. Inspired by "chainmail protection" carbonaceous materials, here we propose an "armor strategy large-scale synthesis a highly active Fe single-atom ORR catalyst (Fe-8/8-CN) pyrolyzing well-designed precursor Fe-ZIF-8/ZIF-8. In this precursor, 2-methylimidazole zinc MOF (ZIF-8) loaded with iron (Fe-ZIF-8) is encased additional ZIF-8 armor layer (Fe-ZIF-8/ZIF-8) that effectively shields species within inner during pyrolysis process, ultimately yielding (Fe-8/8-CN). Furthermore, approaches construction Fe-ZIF-8/ZIF-8 make it efficiently scale up yield 18.7 kg m–3 day–1. particular, protection preparing universally applicable leaf-shaped ZIF-L other ZIFs diverse morphologies. Thanks presence outer core dispersing catalytic sites porous defect-rich characteristics volatilization Zn ZIF-8, resulting Fe-8/8-CN demonstrates superior performance alkaline electrolyte (E1/2 = 0.93 V, JL −5.89 mA cm–2). Finally, Fe-8/8-CN, as cathode material flexible zinc–air batteries, exhibits peak power density (97 mW cm–2) excellent durability Pt/C.

Language: Английский

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Metal–Organic Framework-Derived Rare Earth Metal (Ce-N-C)-Based Catalyst for Oxygen Reduction Reactions in Dual-Chamber Microbial Fuel Cells

Catalysts, Journal Year: 2024, Volume and Issue: 14(8), P. 506 - 506

Published: Aug. 5, 2024

Pt supported on carbon (Pt/C) is deemed as the state-of-the-art catalyst towards oxygen reduction reactions (ORRs) in chemical and biological fuel cells. However, due to high cost scarcity of Pt, researchers have focused development Earth-abundant non-precious metal catalysts, hoping replace traditional Pt/C successfully commercialize In this regard, electrocatalysts made transition metals emerged excellent candidates for ORRs, especially Fe Co combination with N-doped carbons, which produce potentially active M-N4-C (M=Co, Fe) ORR sites. At present, however, metal-based catalysts are popular; recently, rare earth emerging efficient fact that also potential form metal-N4-C sites, just like Fe-N4-C/Co-N4-C. addition, mixed valance states uniqueness f-orbitals believed improve redox properties helps enhancing activity. Among metals, Ce most interesting element can be explored an electrocatalyst carbon. Unique induce distinctive electronic behavior stable coordination structures addition its ability scavenge OH● produced during therefore helping stability. study, we synthesized Ce/N-C by a metal–organic framework pyrolysis strategy. The activity has been optimized systematically increasing content performing RDE studies 0.1 M HClO4 electrolyte. characterized both physicochemical electrochemical characterizations. Ce/N-C-3 exhibited half-wave 0.68 V vs. RHE. delivered acceptable stability loss 70 mV when compared 110 (10 wt.%) catalyst, after 5000 cycles. When used cathode dual-chamber microbial cells, it volumetric power density ~300 mW m−3, along organic matter degradation 74% continuous operation DCMFCs 30 days.

Language: Английский

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Synergistically Promoting Oxygen Electrocatalysis through the Precise Integration of Atomically‐Dispersed Fe Sites and Co Nanoparticles

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 26, 2024

Abstract Oxygen electrochemistry, which encompasses the oxygen reduction reaction (ORR) and evolution (OER), is of utmost importance in energy‐related reactions such as zinc‐air batteries (ZABs). However, due to their four‐electron transfer process, these are still significantly restricted by sluggish kinetics. Supporting atomically‐dispersed (AD) catalyst or metal nanoparticles (NPs) on nitrogen‐doped carbon (NC) proven be an effective strategy for enhancing performance electrocatalysis. Nevertheless, types catalysts fails meet critical requirements ZABs. Herein, a novel Fe AD Co NPs @NC, consists both Fe‐N 1 sites lattice, developed. Spectroscopy studies density functional theory calculations indicate that site lattice facilitates conversion amorphous CoOOH, serves main active ORR. @NC demonstrates remarkable activity OER When it used air‐electrode ZABs, power 247.49 mW cm −2 . This work presents simple yet efficient method enhance electrochemical through synergy between NPs.

Language: Английский

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Synergy of Pyridinic‐N and Co Single Atom Sites for Enhanced Oxygen Redox Reactions in High‐Performance Zinc‐Air Batteries

Small, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

Abstract Cobalt single‐atom catalysts (SACs) have the potential to act as bi‐functional electrocatalysts for oxygen‐redox reactions in metal‐air batteries. However, achieving both high performance and stability these SACs has been challenging. Here, a novel facile synthesis method is used create cobalt‐doped‐nitrogen‐carbon structures (Co‐N‐C) containing cobalt‐SACs by carbonizing modified ZIF‐11. HAADF‐STEM images EXAFS spectra confirmed that structure with lowest cobalt concentration contains single atoms coordinated four nitrogen (Co‐N₄). Electrochemical tests showed this electrocatalyst performed exceptionally well oxygen reduction reaction (ORR) (E1/2 ≈ 0.859 V) evolution (OER) (Ej = 10: 1.544 V), excellent stability. When air cathode of rechargeable zinc‐air battery (ZAB), peak power density 178.6.1 mW cm −2 , specific capacity 799 mA h g Zn −1 cycle‐life 1580 achieved. Density functional theory (DFT) calculations revealed position pyridinic Co play critical role determining overpotential reactions. The unprecedented can bring paradigm changes practical realization application

Language: Английский

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