Engineering Dual Single‐Atom Sites on 2D Ultrathin N‐doped Carbon Nanosheets Attaining Ultra‐Low‐Temperature Zinc‐Air Battery

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(12)

Published: Jan. 7, 2022

Herein, a novel dual single-atom catalyst comprising adjacent Fe-N4 and Mn-N4 sites on 2D ultrathin N-doped carbon nanosheets with porous structure (FeMn-DSAC) was constructed as the cathode for flexible low-temperature Zn-air battery (ZAB). FeMn-DSAC exhibits remarkable bifunctional activities oxygen reduction reaction (ORR) evolution (OER). Control experiments density functional theory calculations reveal that catalytic activity arises from cooperative effect of Fe/Mn dual-sites aiding *OOH dissociation well nanosheet promoting active sits exposure mass transfer during process. The excellent enables ZAB to operate efficiently at ultra-low temperature -40 °C, delivering 30 mW cm-2 peak power retaining up 86 % specific capacity room counterpart.

Language: Английский

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Oxygen Evolution/Reduction Reaction Catalysts: From In Situ Monitoring and Reaction Mechanisms to Rational Design

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(9), P. 6257 - 6358

Published: March 21, 2023

The oxygen evolution reaction (OER) and reduction (ORR) are core steps of various energy conversion storage systems. However, their sluggish kinetics, i.e., the demanding multielectron transfer processes, still render OER/ORR catalysts less efficient for practical applications. Moreover, complexity catalyst–electrolyte interface makes a comprehensive understanding intrinsic mechanisms challenging. Fortunately, recent advances in situ/operando characterization techniques have facilitated kinetic monitoring under conditions. Here we provide selected highlights mechanistic studies with main emphasis placed on heterogeneous systems (primarily discussing first-row transition metals which operate basic conditions), followed by brief outlook molecular catalysts. Key sections this review focused determination true active species, identification sites, reactive intermediates. For in-depth insights into above factors, short overview metrics accurate characterizations is provided. A combination obtained time-resolved information reliable activity data will then guide rational design new Strategies such as optimizing restructuring process well overcoming adsorption-energy scaling relations be discussed. Finally, pending current challenges prospects toward development homogeneous presented.

Language: Английский

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Iron atom–cluster interactions increase activity and improve durability in Fe–N–C fuel cells

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: May 26, 2022

Simultaneously increasing the activity and stability of single-atom active sites M-N-C catalysts is critical but remains a great challenge. Here, we report an Fe-N-C catalyst with nitrogen-coordinated iron clusters closely surrounding Fe-N4 for oxygen reduction reaction in acidic fuel cells. A strong electronic interaction built between satellite due to unblocked electron transfer pathways very short interacting distances. The optimize adsorption strength intermediates on also shorten bond amplitude incoherent vibrations. As result, both are increased by about 60% terms turnover frequency demetalation resistance. This work shows potential interactions multiphase metal species improvements catalysts.

Language: Английский

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Identifying and tailoring C–N coupling site for efficient urea synthesis over diatomic Fe–Ni catalyst

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Sept. 10, 2022

Electrocatalytic urea synthesis emerged as the promising alternative of Haber-Bosch process and industrial synthetic protocol. Here, we report that a diatomic catalyst with bonded Fe-Ni pairs can significantly improve efficiency electrochemical synthesis. Compared isolated single-atom catalysts, act efficient sites for coordinated adsorption activation multiple reactants, enhancing crucial C-N coupling thermodynamically kinetically. The performance up to an order magnitude higher than those electrocatalysts, high yield rate 20.2 mmol h-1 g-1 corresponding Faradaic 17.8% has been successfully achieved. A total about 100% formation value-added urea, CO, NH3 was realized. This work presents insight into synergistic catalysis towards sustainable via identifying tailoring atomic site configurations.

Language: Английский

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Anion-exchange membrane water electrolyzers and fuel cells

Chemical Society Reviews, Journal Year: 2022, Volume and Issue: 51(23), P. 9620 - 9693

Published: Jan. 1, 2022

The key components, working management, and operating techniques of anion-exchange membrane water electrolyzers fuel cells are reviewed for the first time.

Language: Английский

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Metal-metal interactions in correlated single-atom catalysts

Science Advances, Journal Year: 2022, Volume and Issue: 8(17)

Published: April 29, 2022

Single-atom catalysts (SACs) include a promising family of electrocatalysts with unique geometric structures. Beyond conventional ones fully isolated metal sites, an emerging class the adjacent single atoms exhibiting intersite metal-metal interactions appear in recent years and can be denoted as correlated SACs (C-SACs). This type provides more opportunities to achieve substantial structural modification performance enhancement toward wider range electrocatalytic applications. On basis clear identification interactions, this review critically examines research progress C-SACs. It shows that control enables regulation atomic structure, local coordination, electronic properties atoms, which facilitate modulation behavior Last, we outline directions for future work design development C-SACs, is indispensable creating high-performing new SAC architectures.

Language: Английский

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Pulsed Nitrate-to-Ammonia Electroreduction Facilitated by Tandem Catalysis of Nitrite Intermediates

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(11), P. 6471 - 6479

Published: March 10, 2023

Electroreduction of nitrate to ammonia offers a promising pathway for nutrient recycling and recovery from wastewater with energy environmental sustainability. There have been considerable efforts on the regulation reaction pathways facilitate nitrate-to-ammonia conversion over competing hydrogen evolution but only limited success. Here, we report Cu single-atom gel (Cu SAG) electrocatalyst that produces NH3 both nitrite under neutral conditions. Given unique mechanism NO2- activation SAGs spatial confinement strengthened kinetics, pulse electrolysis strategy is presented cascade accumulation intermediates during NO3- reduction prohibited competition reaction, thus substantially enhancing Faradaic efficiency yield rate production compared constant potential electrolysis. This work underlines cooperative approach three-dimensional (3D) framework structures highly efficient enabled by tandem catalysis unfavorable intermediates.

Language: Английский

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Atomically dispersed materials: Ideal catalysts in atomic era

Nano Research, Journal Year: 2023, Volume and Issue: 17(1), P. 18 - 38

Published: May 25, 2023

Language: Английский

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Coordination Symmetry Breaking of Single‐Atom Catalysts for Robust and Efficient Nitrate Electroreduction to Ammonia

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(36)

Published: July 16, 2022

Nitrate electrocatalytic reduction (NO3 RR) for ammonia production is a promising strategy to close the N-cycle from nitration contamination, as well an alternative Haber-Bosch process with less energy consumption and carbon dioxide release. However, current long-term stability of NO3 RR catalysts usually tens hours, far requirements industrialization. Here, symmetry-broken Cusingle-atom are designed, catalytic activity retained after operation more than 2000 h, while average rate 27.84 mg h-1 cm-2 at industrial level density 366 mA achieved, obtaining good balance between stability. Coordination symmetry breaking achieved by embedding one Cu atom in graphene nanosheets two N O atoms cis-configuration, effectively lowering coordination symmetry, rendering active site polar, accumulating NO3- near electrocatalyst surface. Additionally, cis-coordination splits 3d orbitals, which generates orbital-symmetry-matched π-complex key intermediate *ONH reduces barrier, compared σ-complex generated other catalysts. These results reveal critical role single-atom catalysts, prompting design coordination-symmetry-broken electrocatalysts toward possible

Language: Английский

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Precisely Constructing Orbital Coupling-Modulated Dual-Atom Fe Pair Sites for Synergistic CO₂ Electroreduction

ACS Energy Letters, Journal Year: 2022, Volume and Issue: 7(2), P. 640 - 649

Published: Jan. 14, 2022

Electrochemical reduction of CO2 (CO2RR) provides an attractive pathway to achieve a carbon-neutral energy cycle. Single-atom catalysts (SAC) have shown unique potential in heterogeneous catalysis, but their structural simplicity prevents them from breaking linear scaling relationships. In this study, we develop feasible strategy precisely construct series electrocatalysts featuring well-defined single-atom and dual-site iron anchored on nitrogen-doped carbon matrix (Fe1–N–C Fe2–N–C). The Fe2–N–C dual-atom electrocatalyst (DAC) achieves enhanced CO Faradaic efficiency above 80% wider applied ranges along with higher turnover frequency (26,637 h–1) better durability compared SAC counterparts. Furthermore, based in-depth experimental theoretical analysis, the orbital coupling between dual sites decreases gap antibonding bonding states *CO adsorption. This research presents new insights into structure–performance relationship CO2RR at atomic scale extends application DACs for electrocatalysis beyond.

Language: Английский

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