Double activation of oxygen intermediates of oxygen reduction reaction by dual inorganic/organic hybrid electrocatalysts

Lee, Dong Gyu; Kim, Su Hwan; Lee, Jiyun; Shin, Seokmin; Joo, Se Hun; Lee, Yeongdae; Park, Chanhyun; Kwon, Young-Hyuk; Kwak, Sang Kyu; Song, Hyun‐Kon

doi:10.1016/j.nanoen.2021.106048

Cited by 7 publications

(6 citation statements)

References 41 publications

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“…At a proton-rich pH1 medium, the HER changed insignificantly with cations (Figure S6b). Therefore, a water molecule adsorbed on catalytic active sites within the Helmholtz layer was sketched to be double-coordinated to (1) a single cation or multiple cations on its oxygen atom and (2) an active site on its hydrogen atom (catalyst(e – )--H 2 O--M x+ ) when strong cations supporting strong CW were present in electrolytes (Figure d). − The tricomponent intermediate was expected to split into catalyst--H (or H ad ) and – HO--M x+ via the double activation (supported by in situ Raman spectra below).…”

Section: Resultsmentioning

confidence: 99%

“…The O–H bonds of water molecules were more easily split in the presence of stronger cations and anomalously dissociated by very strong Be 2+ . From the standpoint of the activation energy gain, the weakening of the O–H bond strength of water molecules in the presence of strong cations with heterogeneous catalysts is interpreted as the double or associative activation − (chemical transformation process where multiple catalysts work in concert to activate reactants or intermediates). The strong cations could be considered as assistant cocatalysts or promoters in the associative configuration of catalyst–H 2 O–Be 2+ , which was met in the double activation of reactants.…”

Section: Discussionmentioning

confidence: 99%

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Double Activation of Water Splitting by Strong Cation–Water Interaction

Cheong,

Lee,

Lee

et al. 2023

J. Phys. Chem. C

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Presented herein is the possibility of activating water molecules associatively by cations in electrolytes, as well as active sites of electrocatalysts. Cation−water interaction (CW), weakening the intramolecular O−H bonds of water molecules, significantly affected dissociation of water molecules in proton-deficient media, resulting in hydrogen evolution reaction (HER) based on water reduction reaction (WRR). Both the quantitative and qualitative hydration nature of cations (i.e., hydration strength and number) determined the strength of CW and therefore the WRR activity. The cationic dependency of CW on electrolytes was confirmed by bulk and surface-specific spectroscopic techniques. After the cation−water complexes based on strong CW (cation(water) n ) were defined as the main reactants for WRR, the intermediate adsorbate on the catalyst surface was suggested to be water molecules doubly coordinated to cations as well as active sites (cation-water-catalyst). The double activation picture of the tricomponent intermediate was strongly supported by the surface-specific Raman spectra, confirming the polarization-induced weakening of the O−H bonds of water molecules near the Pt catalyst surface in addition to the CWinduced O−H weakening found in the electrolyte as well as on the catalyst surface. The smallest divalent Be 2+ among a series of test cations, including the monovalent, divalent, and trivalent ones, showed the most remarkable WRR kinetic gain, the superiority of which was expected from its high charge density nature guaranteeing strong hydration strength and cationic acidity. The beryllium anomaly to eminently weaken the O−H bonds accelerated WRR at pH2 with 600 mV overpotential gain for 150 mA cm −2 hydrogen production (c.f., 28 mA cm −2 with Na + ).

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Double Activation of Water Splitting by Strong Cation–Water Interaction

Cheong,

Lee,

Lee

et al. 2023

J. Phys. Chem. C

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“…Polypyrrole (pPy) was used as an additive promoter to modify the adsorption energies of the oxygen-containing intermediates via double activation . In our previous work, we demonstrated that the ORR catalytic activities of cobalt-containing oxides were improved by pPy. pPy affected the adsorption of the intermediate oxygen species on the transition metal active sites of the oxides by donating electrons and protons to the intermediates.…”

Section: Resultsmentioning

confidence: 99%

“…It was suggested that this improvement in catalytic activity was ascribed to electron and proton donation from pPy to the oxygen-containing intermediates adsorbed on the catalyst active site (Figure 1a). 26 That is to say, this promoter played a similar role to the proton donor in Busch et al's calculation work so that the LSR breakage is possibly expected. In this work, we present a series of catalyst families having their own LSR different from the known metal LSR for ORR (circumventing).…”

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confidence: 79%

“…Resultantly, the presence of pPy significantly improved the ORR catalytic activities of oxide catalysts. It was suggested that this improvement in catalytic activity was ascribed to electron and proton donation from pPy to the oxygen-containing intermediates adsorbed on the catalyst active site (Figure a) . That is to say, this promoter played a similar role to the proton donor in Busch et al’s calculation work so that the LSR breakage is possibly expected.…”

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confidence: 89%

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Breaking the Linear Scaling Relationship by a Proton Donor for Improving Electrocatalytic Oxygen Reduction Kinetics

et al. 2021

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Theoretical computational studies have claimed that the catalytic activity of a family of heterogeneous catalysts (e.g., metal catalysts) is governed by a linear scaling relationship (LSR) between adsorption energy levels of intermediates on active sites of catalysts. The volcano shape of the activity versus the adsorption energy of one of the intermediates was obtained from the LSR and the Brønsted–Evans–Polanyi relationship. An improved activity can be achieved using a catalyst having optimized adsorption energy of the volcano or alternatively by circumventing or breaking the LSR. Herein, we demonstrated that the LSR of a series of transition metal terephthalates (MTPs; M = Fe, Co, Ni, Cu, or Zn) as electrocatalysts for the oxygen reduction reaction (ORR) was broken in the presence of polypyrrole (pPy) as a proton donor. The reason for the LSR breakage was that the intermediate to which the proton of pPy was delivered was different depending on the metal of MTP. Also, pPy affected the adsorption energy of the specific intermediate (the target of the proton transfer) more strongly while the other intermediates were less affected by pPy. Experimentally as well as theoretically, pPy significantly improved the ORR activity of MTPs, altering the activity volcano plot. The most significant improvement was found on CoTP: the onset potential of ORR on CoTP was shifted toward the more easy-to-be-reduced direction from 0.7 to 0.85 VRHE at 1 mA cm–2.

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Electronic State Modulation and Reaction Pathway Regulation on Necklace‐Like MnO_x‐CeO₂@Polypyrrole Hierarchical Cathode for Advanced and Flexible Li–CO₂ Batteries

Deng

Yang

Mao

et al. 2022

Advanced Energy Materials

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Li–CO2 batteries provide the possibility for synchronous implementation of carbon neutrality and development of advanced energy storage devices. Catalytic cathodes composed of well‐designed conductive substrates and active materials are critical to the improvement of Li–CO2 batteries. Herein, MnOx‐CeO2 hollow nanospheres are strung together by conductive polypyrrole (PPy) via post‐in‐situ polymerization, and a necklace‐like MnOx‐CeO2@PPy hierarchical cathode with excellent flexibility and self‐supporting feature is constructed. Benefitting from the excellent conductivity of PPy, the binder‐free structure, and the greatly exposed catalytic active sites, the MnOx‐CeO2@PPy based Li–CO2 batteries exhibit superior discharge capacity (13631 mA h g–1 at 100 mA g–1) and cycle performance (253 cycles) as well as a low overpotential of 1.49 V. Of particular note, the flexible freestanding film is confirmed as a potential catalytic cathode for flexible Li–CO2 batteries. The density functional theory calculations, combined with experimental tests, are performed to gain insights into the enhanced substrate adsorption capacity, the optimized electronic structure of the active surface MnOx‐CeO2 (111), the concentrated electrons on the reaction sites Ce, and the electrochemical mechanism. This work initiates the use of conductive polymers for catalytic cathodes in Li–CO2 batteries, which provide new opportunities for promoting the performance of various energy storage devices.

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Double activation of oxygen intermediates of oxygen reduction reaction by dual inorganic/organic hybrid electrocatalysts

Cited by 7 publications

References 41 publications

Double Activation of Water Splitting by Strong Cation–Water Interaction

Double Activation of Water Splitting by Strong Cation–Water Interaction

Breaking the Linear Scaling Relationship by a Proton Donor for Improving Electrocatalytic Oxygen Reduction Kinetics

Electronic State Modulation and Reaction Pathway Regulation on Necklace‐Like MnO_x‐CeO₂@Polypyrrole Hierarchical Cathode for Advanced and Flexible Li–CO₂ Batteries

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Double activation of oxygen intermediates of oxygen reduction reaction by dual inorganic/organic hybrid electrocatalysts

Cited by 7 publications

References 41 publications

Double Activation of Water Splitting by Strong Cation–Water Interaction

Double Activation of Water Splitting by Strong Cation–Water Interaction

Breaking the Linear Scaling Relationship by a Proton Donor for Improving Electrocatalytic Oxygen Reduction Kinetics

Electronic State Modulation and Reaction Pathway Regulation on Necklace‐Like MnOx‐CeO2@Polypyrrole Hierarchical Cathode for Advanced and Flexible Li–CO2 Batteries

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Product

Resources

About

Electronic State Modulation and Reaction Pathway Regulation on Necklace‐Like MnO_x‐CeO₂@Polypyrrole Hierarchical Cathode for Advanced and Flexible Li–CO₂ Batteries