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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Electrochemical Water Splitting: Bridging the Gaps Between Fundamental Research and Industrial Applications

Energy & environment materials, Journal Year: 2022, Volume and Issue: 6(5)

Published: May 28, 2022

Electrochemical water splitting represents one of the most promising technologies to produce green hydrogen, which can help realize goal achieving carbon neutrality. While substantial efforts on a laboratory scale have been made for understanding fundamental catalysis and developing high‐performance electrocatalysts two half‐reactions involved in electrocatalysis, much less attention has paid doing relevant research larger scale. For example, few such researches done an industrial Herein, we review very recent endeavors bridge gaps between applications electrolysis. We begin by introducing fundamentals electrochemical then present comparisons testing protocol, figure merit, catalyst interest, manufacturing cost industry‐based water‐electrolysis research. Special is tracking surface reconstruction process identifying real catalytic species under different conditions, highlight significant distinctions corresponding mechanisms. Advances designs industry‐relevant electrolysis are also summarized, reveal progress moving practical forward accelerating synergies material science engineering. Perspectives challenges electrocatalyst design strategies proposed finally further lab‐scale large‐scale electrocatalysis applications.

Language: Английский

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Bifunctional Electrocatalysts for Overall and Hybrid Water Splitting

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(7), P. 3694 - 3812

Published: March 22, 2024

Electrocatalytic water splitting driven by renewable electricity has been recognized as a promising approach for green hydrogen production. Different from conventional strategies in developing electrocatalysts the two half-reactions of (e.g., and oxygen evolution reactions, HER OER) separately, there growing interest designing bifunctional electrocatalysts, which are able to catalyze both OER. In addition, considering high overpotentials required OER while limited value produced oxygen, is another rapidly exploring alternative oxidation reactions replace hybrid toward energy-efficient generation. This Review begins with an introduction on fundamental aspects splitting, followed thorough discussion various physicochemical characterization techniques that frequently employed probing active sites, emphasis reconstruction during redox electrolysis. The design, synthesis, performance diverse based noble metals, nonprecious metal-free nanocarbons, overall acidic alkaline electrolytes, thoroughly summarized compared. Next, their application also presented, wherein anodic include sacrificing agents oxidation, pollutants oxidative degradation, organics upgrading. Finally, concise statement current challenges future opportunities presented hope guiding endeavors quest sustainable

Language: Английский

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Simultaneously Engineering the Synergistic-Effects and Coordination-Environment of Dual-Single-Atomic Iron/Cobalt-sites as a Bifunctional Oxygen Electrocatalyst for Rechargeable Zinc-Air Batteries

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(4), P. 2313 - 2325

Published: Jan. 30, 2023

Single-atom introduced carbon nanomaterials show favorable oxygen-reduction reaction (ORR) and oxygen-evolution (OER) performance for renewable energy applications. Nevertheless, the electronic-structure regulation by decorating heterogeneous single-metal-atoms engineering of a single-atom active-sites' microenvironment need to be optimized simultaneously, which is challenging. Herein, we develop an atomic-interfacial-regulation approach fabricate dual single Fe/Co atoms synchronized with both nitrogen/sulfur on defective/graphitic/porous nanosheets (Fe,Co/DSA-NSC). The unsymmetrically organized N S coordinated bridged atomic-sites [Fe-(N2S)/Co-(N2S) moiety] are established prompt charge-transfer, lowering barrier oxygenated reaction-intermediates leading boost reaction-kinetics. As estimated, Fe,Co/DSA-NSC exhibits improved ORR/OER activity higher half-wave potential lower overpotential (E1/2 = 879 mV η10 210 mV, respectively) also good cycling stability toward zinc-air batteries. This discovery hence provides widespread scheme synergistic-principles dual-single-atom catalysts controlled

Language: Английский

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Integration of Alloy Segregation and Surface CoO Hybridization in Carbon‐Encapsulated CoNiPt Alloy Catalyst for Superior Alkaline Hydrogen Evolution

Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 33(41)

Published: July 28, 2023

Abstract Constructing an efficient alkaline hydrogen evolution reaction (HER) catalyst with low platinum (Pt) consumption is crucial for the cost reduction of energy devices, such as electrolyzers. Herein, nanoflower‐like carbon‐encapsulated CoNiPt alloy catalysts composition segregation are designed by pyrolyzing morphology‐controlled and Pt‐proportion‐tuned metal–organic frameworks (MOFs). The optimized containing 15% NFs (15%: Pt mass percentage, NFs: nanoflowers) exhibits outstanding HER performance a overpotential 25 mV at current density 10 mA cm −2 , far outperforming those commercial Pt/C (47 mV) most advanced catalysts. Such superior activity originates from integration Co‐O hybridization. hierarchical structure guarantees full exposure sites. Density functional theory calculations suggest that components not only promote water dissociation but also facilitate adsorption process, synergistically accelerating kinetics HER. In addition, volcanically distributed surface oxygen content, mainly in form Co 3d O 2p hybridization, which another reason enhanced activity. This work provides feasible insights into design cost‐effective coordinating kinetic sites adjusting appropriate content.

Language: Английский

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Charge transfer of carbon nanomaterials for efficient metal‐free electrocatalysis

Interdisciplinary materials, Journal Year: 2022, Volume and Issue: 1(1), P. 28 - 50

Published: Jan. 1, 2022

Abstract Recently, carbon‐based metal‐free electrocatalysts (C‐MFECs) have drawn considerable research attention because of their attractive physicochemical characteristics, cost‐effectiveness, and ability to convert store energy efficiently. Efficient intramolecular charge transfer among different parts the carbon electrocatalyst and/or intermolecular between electrolyte dictate ultimate conversion performance. Experimental results theoretical analyses demonstrated that rational design nanomaterials, coupled with proper through heteroatom doping, incorporation Stone–Wales defects, adsorption appropriate molecules/moieties, can promote efficient electrocatalysis. In this article, we will first provide related principles then present an overview on development C‐MFECs for transfer, followed by elucidating charge‐transfer processes electrocatalytic reactions renewable environmental remediation technologies. Finally, current challenges future perspectives in exciting field be discussed.

Language: Английский

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Ultrahigh oxygen-doped carbon quantum dots for highly efficient H₂O₂ production via two-electron electrochemical oxygen reduction

Energy & Environmental Science, Journal Year: 2022, Volume and Issue: 15(10), P. 4167 - 4174

Published: Jan. 1, 2022

Ultrahigh oxygen doping content in carbon quantum dots enables excellent H 2 O selectivity and great potential on-site green production.

Language: Английский

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Challenges and prospects of lithium–CO₂batteries

Deleted Journal, Journal Year: 2022, Volume and Issue: 1, P. e9120001 - e9120001

Published: March 21, 2022

The key role played by carbon dioxide in global temperature cycles has stimulated constant research attention on capture and storage. Among the various options, lithium–carbon batteries are intriguing, not only for transformation of waste to value-added products, but also storage electricity from renewable power resources balancing cycle. development this system is still its early stages faces tremendous hurdles caused introduction dioxide. In review, detailed discussion critical problems faced electrode, interface, electrolyte provided, along with rational strategies required address these problematic issues efficient fixation conversion. We hope that review will provide a resource comprehensive understanding serve as guidance exploring reversible rechargeable alkali metal-based battery systems future.

Language: Английский

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Carbon-based catalyst supports for oxygen reduction in proton-exchange membrane fuel cells

Trends in Chemistry, Journal Year: 2022, Volume and Issue: 4(10), P. 886 - 906

Published: Aug. 26, 2022

Language: Английский

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Potassium‐Assisted Fabrication of Intrinsic Defects in Porous Carbons for Electrocatalytic CO₂ Reduction

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(42)

Published: Aug. 11, 2022

The fabrication of intrinsic carbon defects is usually tangled with doping effects, and the identification their unique roles in catalysis remains a tough task. Herein, K+ -assisted synthetic strategy developed to afford porous (K-defect-C) abundant complete elimination heteroatom via direct pyrolysis -confined metal-organic frameworks (MOFs). Positron-annihilation lifetime spectroscopy, X-ray absorption fine structure measurement, scanning transmission electron microscopy jointly illustrate existence 12-vacancy-type (V12 ) K-defect-C. Remarkably, K-defect-C achieves ultrahigh CO Faradaic efficiency (99%) at -0.45 V CO2 electroreduction, far surpassing MOF-derived without etching. Theoretical calculations reveal that V12 favor adsorption significantly accelerate formation rate-determining COOH* intermediate, thereby promoting reduction. This work develops novel generate provides new insights into critical role catalysis.

Language: Английский

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