Optimizing Fe‐3d Electron Delocalization by Asymmetric Fe–Cu Diatomic Configurations for Efficient Anion Exchange Membrane Fuel Cells

Advanced Energy Materials, Journal Year: 2023, Volume and Issue: 13(46)

Published: Oct. 27, 2023

Abstract Precisely designing asymmetric diatomic configurations and studying their electronic regulation effect for improving the oxygen reduction reaction (ORR) performance are important anion exchange membrane fuel cells (AEMFCs). Here, a Fe, Cu co‐doped 2D crystalline IISERP‐MOF27 nanosheet derived FeN 3 O‐CuN 4 site nanocatalyst (named as FeCu‐NC) is synthesized cathodes of AEMFCs. Thanks to optimal structure in FeCu‐NC catalyst, it shows enhanced half‐wave potential (0.910 V), turnover frequency (0.165e s −1 ), decreased activation energy (19.96 kJ mol ) KOH. The FeCu‐NC‐based AEMFC achieves extremely high kinetic current (0.138 A cm −2 at 0.9 V) rated power density (1.09 W surpassing best‐reported transition metal‐based cathodes. Density functional theory calculations further demonstrate that Cu‐N can break localization Fe‐3d orbitals, accelerate electron transport, optimize OH adsorption, thus facilitating ORR process.

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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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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Transformation of the Active Moiety in Phosphorus-Doped Fe–N–C for Highly Efficient Oxygen Reduction Reaction

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(14), P. 9427 - 9441

Published: July 3, 2023

Iron- and nitrogen-doped carbon (Fe–N–C) materials have been suggested as the most promising replacement for Pt-based catalysts in oxygen reduction reaction (ORR) owing to FeN4 active moiety. Based on relationship between binding energy catalytic activity, Fe–N–C has a very strong energy; hence, hard desorb final intermediate of *OH. Herein, we provide an effective method tuning moiety using phosphine-gas treatment Fe–N–C. Combined analyses experimental computational results reveal that conventional is transformed into FeN3PO through P-doping post-treatment. Furthermore, propose ORR mechanism unique based microkinetic model, which *OH intermediates are considered. Compared moiety, facilitates desorption, thereby enhancing activity both alkaline acidic electrolytes. The effects performance also validated anion exchange membrane fuel cells (AEMFCs) proton (PEMFCs).

Language: Английский

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Activity versus stability of atomically dispersed transition-metal electrocatalysts

Nature Reviews Materials, Journal Year: 2024, Volume and Issue: 9(9), P. 643 - 656

Published: July 31, 2024

Language: Английский

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Frustrated Lewis Pairs on Zr Single Atoms Supported N‐Doped TiO_2‐x Catalysts for Electrochemical Nitrate Reduction To Ammonia

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: 34(36)

Published: Feb. 29, 2024

Abstract The electrochemical reduction of nitrates (NO 3 RR) for ammonia synthesis at room temperature holds immense potential. One key challenge is the adsorption and activation NO − , along with provision sufficient active hydrogen to accelerate hydrogenation process. Here, study prepares N‐doped TiO 2‐x supported by Zr single atoms (Zr‐TiON) rich oxygen vacancies (O v ), in which unsaturated (Lewis acidic, LA) sites together around O base, LB) form frustrated Lewis acid‐base pairs (FLPs). At −60 mA cm −2 NH Faradaic efficiency reaches 94.8%, corresponding production rate 663.15 µmol h −1 mg cat . yield up 26.16 mmol A flowing electrolyzer. Theoretical calculations situ spectroscopy analysis reveal that interaction between LA LB FLPs plays a crucial role facilitating electron‐rich electron‐deficient * H. presence enhanced significantly reduces energy barrier H 2 dissociation, lowering it 0.20 eV, facilitates subsequent reactions. abundance accelerates process, thereby enhancing activity RR. This FLP design offers promising approach paving way development highly efficient RR catalysts.

Language: Английский

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Materials Containing Single‐, Di‐, Tri‐, and Multi‐Metal Atoms Bonded to C, N, S, P, B, and O Species as Advanced Catalysts for Energy, Sensor, and Biomedical Applications

Advanced Science, Journal Year: 2024, Volume and Issue: 11(33)

Published: July 1, 2024

Abstract Modifying the coordination or local environments of single‐, di‐, tri‐, and multi‐metal atom (SMA/DMA/TMA/MMA)‐based materials is one best strategies for increasing catalytic activities, selectivity, long‐term durability these materials. Advanced sheet supported by metal atom‐based have become a critical topic in fields renewable energy conversion systems, storage devices, sensors, biomedicine owing to maximum utilization efficiency, precisely located centers, specific electron configurations, unique reactivity, precise chemical tunability. Several offer excellent support are attractive applications energy, medical research, such as oxygen reduction, production, hydrogen generation, fuel selective detection, enzymatic reactions. The strong metal–metal metal–carbon with metal–heteroatom (i.e., N, S, P, B, O) bonds stabilize optimize electronic structures atoms due interfacial interactions, yielding activities. These provide models understanding fundamental problems multistep This review summarizes substrate structure‐activity relationship different active sites based on experimental theoretical data. Additionally, new synthesis procedures, physicochemical characterizations, biomedical discussed. Finally, remaining challenges developing efficient SMA/DMA/TMA/MMA‐based presented.

Language: Английский

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Precisely Constructing Orbital‐Coupled Fe─Co Dual‐atom Sites for High‐Energy‐Efficiency Zn–Air/Iodide Hybrid Batteries

Advanced Materials, Journal Year: 2024, Volume and Issue: 36(32)

Published: May 30, 2024

Abstract Rechargeable Zn–air batteries (ZABs) are promising for energy storage and conversion. However, the high charging voltage low efficiency hinder their commercialization. Herein, these challenges addressed by employing precisely constructed multifunctional Fe–Co diatomic site catalysts (FeCo‐DACs) integrating iodide/iodate redox into ZABs to create Zinc–air/iodide hybrid (ZAIHBs) with highly efficient catalyst. The strong coupling between 3d orbitals of Fe Co weakens excessively binding strength active sites intermediates, enhancing catalytic activities oxygen reduction/evolution reaction redox. Consequently, FeCo‐DACs exhibit outstanding bifunctional activity a small potential gap (Δ E = 0.66 V) stability. Moreover, an performance toward is obtained. Therefore, FeCo‐DAC‐based ZAIHBs up 75% at 10 mA cm −2 excellent cycling stability (72% after 500 h). This research offers critical insights rational design DACs paves way high‐energy devices.

Language: Английский

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Asymmetric Coordination of Bimetallic Fe–Co Single-Atom Pairs toward Enhanced Bifunctional Activity for Rechargeable Zinc–Air Batteries

ACS Nano, Journal Year: 2024, Volume and Issue: 18(20), P. 13006 - 13018

Published: May 13, 2024

The advancement of rechargeable zinc–air batteries (RZABs) faces challenges from the pronounced polarization and sluggish kinetics oxygen reduction evolution reactions (ORR OER). Single-atom catalysts offer an effective solution, yet their insufficient or singular catalytic activity hinders development. In this work, a dual single-atom catalyst, FeCo-SAs, was fabricated, featuring atomically dispersed N3–Fe–Co–N4 sites on N-doped graphene nanosheets for bifunctional activity. Introducing Co into Fe single-atoms secondary pyrolysis altered coordination with N, creating asymmetric environment that promoted charge transfer increased density states near Fermi level. This catalyst achieved narrow potential gap 0.616 V, half-wave 0.884 V ORR (vs reversible hydrogen electrode) low OER overpotential 270 mV at 10 mA cm–2. Owing to superior RZABs exhibited peak power 203.36 mW cm–2 extended cycle life over 550 h, exceeding commercial Pt/C + IrO2 catalyst. Furthermore, flexible FeCo-SAs demonstrated promising future bimetallic pairs in wearable energy storage devices.

Language: Английский

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Structure–Activity Relationships in Oxygen Electrocatalysis

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

Published: Sept. 30, 2024

Abstract Oxygen electrocatalysis, as the pivotal circle of many green energy technologies, sets off a worldwide research boom in full swing, while its large kinetic obstacles require remarkable catalysts to break through. Here, based on summarizing reaction mechanisms and situ characterizations, structure–activity relationships oxygen electrocatalysts are emphatically overviewed, including influence geometric morphology chemical structures electrocatalytic performances. Subsequently, experimental/theoretical is combined with device applications comprehensively summarize cutting‐edge according various material categories. Finally, future challenges forecasted from perspective catalyst development applications, favoring researchers promote industrialization electrocatalysis at an early date.

Language: Английский

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