Sabatier Relations in Electrocatalysts Based on High‐entropy Alloys with Wide‐distributed d‐band Centers for Li‐O₂ Batteries

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(44)

Published: Sept. 12, 2023

Li-O2 battery (LOB) is a promising "beyond Li-ion" technology with ultrahigh theoretical energy density (3457 Wh kg-1 ), while currently impeded by the sluggish cathodic kinetics of reversible gas-solid reaction between O2 and Li2 . Despite many catalysts are developed for accelerating conversion process, lack design guidance achieving high performance makes exploring aleatory. The Sabatier principle an acknowledged theory connecting scaling relationship heterogeneous catalytic activity, providing tradeoff strategy topmost performance. Herein, series wide-distributed d-band centers (i.e., wide range adsorption strength) elaborately constructed via high-entropy strategy, enabling in-depth study relations in electrocatalysts LOBs. A volcano-type correlation center activity emerges. Both experimental results indicate that moderate appropriate strength propels up to top. As demonstration concept, LOB using FeCoNiMnPtIr as catalyst provides exceptional efficiency over 80 %, works steadily 2000 h fixed specific capacity 4000 mAh g-1 This work certifies applicability designing advanced assembled

Language: Английский

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Why do Single‐Atom Alloys Catalysts Outperform both Single‐Atom Catalysts and Nanocatalysts on MXene?

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(4)

Published: Dec. 1, 2023

Abstract Single‐atom alloys (SAAs), combining the advantages of single‐atom and nanoparticles (NPs), play an extremely significant role in field heterogeneous catalysis. Nevertheless, understanding catalytic mechanism SAAs catalysis reactions remains a challenge compared with single atoms NPs. Herein, ruthenium‐nickel (RuNi ) synthesized by embedding atomically dispersed Ru Ni NPs are anchored on two‐dimensional Ti 3 C 2 T x MXene. The RuNi SAA‐3 −Ti catalysts exhibit unprecedented activity for hydrogen evolution from ammonia borane (AB, NH BH hydrolysis mass‐specific (r mass value 333 L min −1 g . Theoretical calculations reveal that anchoring optimizes dissociation AB H O as well binding ability H* intermediates during due to d‐band structural modulation caused alloying effect metal‐supports interactions (MSI) This work provides useful design principles developing optimizing efficient hydrogen‐related demonstrates over energy

Language: Английский

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Optimizing Electrocatalytic Nitrogen Reduction via Interfacial Electric Field Modulation: Elevating d‐Band Center in WS₂‐WO₃ for Enhanced Intermediate Adsorption

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(29)

Published: May 25, 2023

Electrocatalytic nitrogen reduction reaction (ENRR) has emerged as a promising approach to synthesizing green ammonia under ambient conditions. Tungsten (W) is one of the most effective ENRR catalysts. In this reaction, protonation intermediates rate-determining step (RDS). Enhancing adsorption crucial increase intermediates, which can lead improved catalytic performance. Herein, we constructed strong interfacial electric field in WS2 -WO3 elevate d-band center W, thereby strengthening intermediates. Experimental results demonstrated that led significantly Specifically, exhibited high NH3 yield 62.38 μg h-1 mgcat-1 and promoted faraday efficiency (FE) 24.24 %. Furthermore, situ characterizations theoretical calculations showed upshifted W towards Fermi level, leading enhanced -NH2 -NH on catalyst surface. This resulted rate RDS. Overall, our study offers new insights into relationship between provides strategy enhance during process.

Language: Английский

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Single‐Atom Immobilization Boosting Oxygen Redox Kinetics of High‐Entropy Perovskite Oxide Toward High‐Performance Lithium‐Oxygen Batteries

Advanced Energy Materials, Journal Year: 2024, Volume and Issue: 14(17)

Published: Jan. 17, 2024

Abstract Understanding and modulating the unique electronic interaction between single‐metal atoms high entropy compounds are of great significance to enable their high‐efficiency oxygen electrocatalysis for aprotic lithium‐oxygen (Li‐O 2 ) batteries. Herein, a novel bi‐functional electrocatalyst is first time created by immobilizing single‐atom ruthenium (Ru) on lanthanum‐based perovskite oxide La(Mn 0.2 Co Fe Ni Cr )O 3 (Ru@HEPO), which demonstrates activity stability in Li‐O The heteronuclear coordination Ru HEPO facilitates fast electron transfer from establishing Ru‐O‐M (M stands Mn, Co, Fe, Ni) bridges, well redistributes electrons within Ru@HEPO hence significantly improving its interfacial charge kinetics electrocatalytic activity. Additionally, strong coupling Mn enhances hybridization 3d O 2p orbitals, promotes inherent affinity toward LiO intermediate, thereby reducing reaction energy barrier electrode. As result, Ru@HEPO‐based batteries deliver remarkable electrochemical performances, such as efficiency (87.3% at 100 mA g −1 ), excellent rate capability (low overpotential 0.52 V durable cyclability (345 cycles 300 ). This work opens up promising avenue development entropy‐based electrocatalysts precisely tailoring distributions an atomic scale.

Language: Английский

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Boosting the ORR/OER Activity of Cobalt‐Based Nano‐Catalysts by Co 3d Orbital Regulation

Small, Journal Year: 2024, Volume and Issue: 20(35)

Published: April 2, 2024

Abstract The transition metal oxides/sulfides are considered promising catalysts due to their abundant resources, facile synthesis, and reasonable electrocatalytic activity. Herein, a significantly improved intrinsic catalytic activity is achieved for constructing Co‐based nanocrystal (Co‐S@NC) with the coordination of Co─S, Co─S─C, Co─N x ─C. calculational experimental results demonstrate that diversified chemical environment Co‐cations induces 3d orbitals high spin‐state exhibits coexistence Co 2+ fully occupied d π 3+ unpaired electrons in orbitals. diverse occupation contributes an elevated d‐band center ions, which accelerates oxygen reduction reaction evolution kinetics Co‐S@NC nanocrystal. Therefore, Li–O 2 batteries as cathode catalyst exhibit 300 cycles at current density 500 mA g −1 cut‐off capacity 1000 mAh . Moreover, ultrahigh discharge specific 34 587 obtained , corresponding energy 949 Wh kg prototype battery. study on orbital regulation nanocrystals provides innovative strategy bifunctional electrocatalysts toward practical application metal–air batteries.

Language: Английский

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Delocalized Electronic Engineering of Ni₅P₄ Nanoroses for Durable Li–O₂ Batteries

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

Published: May 11, 2023

The sluggish kinetics and issues associated with the parasitic reactions of cathodes are major obstacles to large-scale application Li-O2 batteries (LOBs), despite their large theoretical energy density. Therefore, efficient electrocatalyst design is critical for optimizing performance. Ni5 P4 analyzed theoretically as a cathode material, downshift d-band center found enhance electron occupation in antibonding orbits, providing valuable descriptor understanding enhancing intrinsic electrocatalytic activity. In this study, it demonstrated that incorporating additional nitrogen atoms into nanoroses regulates electronic structure, resulting superior performance LOBs. Further spectroscopic analysis density functional theory calculations reveal incorporated sites can effectively induce localized structure polarization, lowering barrier production desirable intermediates thus battery capacity preventing cell degradation. This approach provides sound basis developing advanced electrode materials optimized structures high-performance

Language: Английский

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Coupling MnS and CoS Nanocrystals on Self-Supported Porous N-doped Carbon Nanofibers to Enhance Oxygen Electrocatalytic Performance for Flexible Zn-Air Batteries

ACS Applied Materials & Interfaces, Journal Year: 2023, Volume and Issue: 15(22), P. 26766 - 26777

Published: May 29, 2023

Seeking highly efficient, stable, and cost-effective bifunctional electrocatalysts of rechargeable Zn–air batteries (ZABs) is the top-priority for developing new generation portable electronic devices. For this, rational effective structural design, interface engineering, electron recombination on should be taken into account to reduce reaction overpotential expedite kinetics oxygen reduction (ORR) evolution (OER). Herein, we construct a MnCo-based metal organic framework-derived heterogeneous MnS–CoS nanocrystals, which are anchored free-standing porous N-doped carbon fibers (PNCFs) by in situ growth method vulcanization process. Benefiting from abundant vacancies active sites, strong interfacial coupling as well favorable conductivity, MnS–CoS/PNCFs composite electrode delivers mentionable electrocatalytic activity stability with half-wave potential 0.81 V ORR an 350 mV OER alkaline medium. Of note, flexible ZAB using binder-free air cathode offers high power density 86.7 mW cm–2, large specific capacity 563 mA h g–1, adapts different bending degree operation. In addition, functional theory calculation clarifies that nanocrystals reduces barrier enhances conductivity catalyst adsorption intermediates during This study opens up insight design self-supported

Language: Английский

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Synthesis and Electrocatalytic Applications of Layer‐Structured Metal Chalcogenides Composites

Small, Journal Year: 2024, Volume and Issue: 20(26)

Published: Jan. 14, 2024

Abstract Featured with the attractive properties such as large surface area, unique atomic layer thickness, excellent electronic conductivity, and superior catalytic activity, layered metal chalcogenides (LMCs) have received considerable research attention in electrocatalytic applications. In this review, approaches developed to synthesize LMCs‐based electrocatalysts are summarized. Recent progress composites for electrochemical energy conversion applications including oxygen reduction reaction, carbon dioxide evolution hydrogen overall water splitting, nitrogen reaction is reviewed, potential opportunities practical obstacles development of high‐performing active substances also discussed. This review may provide an inspiring guidance developing high‐performance LMCs

Language: Английский

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Unlocking the critical roles of N, P Co-Doping in MXene for Lithium‐Oxygen Batteries: Elevated d‐Band center and expanded interlayer spacing

Journal of Colloid and Interface Science, Journal Year: 2024, Volume and Issue: 676, P. 368 - 377

Published: July 18, 2024

Language: Английский

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TiN as Radical Scavenger in Fe─N─C Aerogel Oxygen Reduction Catalyst for Durable Fuel Cell

Small, Journal Year: 2024, Volume and Issue: 20(30)

Published: Feb. 23, 2024

Abstract Fe─N─C is the most promising alternative to platinum‐based catalysts lower cost of proton‐exchange‐membrane fuel cell (PEMFC). However, deficient durability has hindered their application. Herein, a TiN‐doped (Fe─N─C/TiN) elaborately synthesized via sol–gel method for oxygen‐reduction reaction (ORR) in PEMFC. The interpenetrating network composed by and TiN can simultaneously eliminate free radical intermediates while maintaining high ORR activity. As result, H 2 O yields Fe─N─C/TiN are suppressed below 4%, ≈4 times than Fe─N─C, half‐wave potential only lost 15 mV after 30 kilo‐cycle accelerated test (ADT). In ─O assembled with Fe─N─C/TiN, it presents 980 mA cm −2 current density at 0.6 V, 880 mW peak power density, 17 voltage loss 0.80 A 10 ADT. experiment calculation results prove that strong adsorption interaction (such as *OH, *OOH, etc.), radicals scavenged subsequently. rational integration Fe single‐atom, scavenger, highly porous adequately utilize intrinsic advantages composite structure, enabling durable active Pt‐metal‐free catalyst

Language: Английский

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