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Wang T, Li W, Wu G. Bioinspired Tetranuclear Manganese Cubane Complex as an Efficient Molecular Electrocatalyst for Two-Electron Water Oxidation Towards Hydrogen Peroxide. Angew Chem Int Ed Engl 2024; 63:e202406701. [PMID: 38740950 DOI: 10.1002/anie.202406701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/07/2024] [Accepted: 05/13/2024] [Indexed: 05/16/2024]
Abstract
Stable homogeneous two-electron water oxidation electrocatalysts are highly demanded to understand the precise mechanism and reaction intermediates of electrochemical H2O2 production. Here we report a tetranuclear manganese complex with a cubane structure which can electrocatalyze water oxidation to hydrogen peroxide under alkaline and neutral conditions. Such a complex demonstrates an optimal Faradaic efficiency (FE) of 87 %, which is amongst (if not) the highest FE(H2O2) of reported homogeneous and heterogeneous electrocatalysts. In addition, active species were identified and co-catalysts were excluded through ESI-MS characterization. Furthermore, we identified water binding sites and isolated one-electron oxidation intermediate by chemical oxidation of the catalyst in the presence of water substrates. It is evident that efficient proton-accepting electrolytes avoid rapid proton building-up at electrode and substantially improve reaction rate and selectivity. Accordingly, we propose a two-electron catalytic cycle model for water oxidation to hydrogen peroxide with the bioinspired molecular electrocatalyst. The present work is expected to provide an ideal platform to elucidate the two-electron WOR mechanism at the atomic level.
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Affiliation(s)
- Tongshuai Wang
- State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China
| | - Wenxiu Li
- State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China
| | - Gang Wu
- State Key Laboratory of Inorganic Synthesis & Preparative Chemistry, Jilin University, 2699 Qianjin Street, Changchun, 130012, P. R. China
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McKenzie ECR, Hosseini S, Petro AGC, Rudman KK, Gerroll BHR, Mubarak MS, Baker LA, Little RD. Versatile Tools for Understanding Electrosynthetic Mechanisms. Chem Rev 2021; 122:3292-3335. [PMID: 34919393 DOI: 10.1021/acs.chemrev.1c00471] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Electrosynthesis is a popular, green alternative to traditional organic methods. Understanding the mechanisms is not trivial yet is necessary to optimize reaction processes. To this end, a multitude of analytical tools is available to identify and quantitate reaction products and intermediates. The first portion of this review serves as a guide that underscores electrosynthesis fundamentals, including instrumentation, electrode selection, impacts of electrolyte and solvent, cell configuration, and methods of electrosynthesis. Next, the broad base of analytical techniques that aid in mechanism elucidation are covered in detail. These methods are divided into electrochemical, spectroscopic, chromatographic, microscopic, and computational. Technique selection is dependent on predicted reaction pathways and electrogenerated intermediates. Often, a combination of techniques must be utilized to ensure accuracy of the proposed model. To conclude, future prospects that aim to enhance the field are discussed.
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Affiliation(s)
- Eric C R McKenzie
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Seyyedamirhossein Hosseini
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Ana G Couto Petro
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Kelly K Rudman
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Benjamin H R Gerroll
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | | | - Lane A Baker
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - R Daniel Little
- Department of Chemistry, University of California Santa Barbara, Building 232, Santa Barbara, California 93106, United States
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Laborda E, García-Martínez J, Molina A. Spectroelectrochemistry for the study of reversible electrode reactions with complex stoichiometries. Electrochem commun 2021. [DOI: 10.1016/j.elecom.2020.106915] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
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Ma J, Yang M, Batchelor-McAuley C, Compton RG. Visualising electrochemical reaction layers: mediated vs. direct oxidation. Phys Chem Chem Phys 2020; 22:12422-12433. [PMID: 32459226 DOI: 10.1039/d0cp01904f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrochemical treatments are widely used for 'clean up' in which toxic metals and organic compounds are removed using direct or mediated electrolysis. Herein we report novel studies offering proof of concept that spectrofluorometric electrochemistry can provide important mechanistic detail into these processes. A thin layer opto-electrochemical cell, with a carbon fibre (radius 3.5 μm) working electrode, is used to visualise the optical responses of the oxidative destruction of a fluorophore either directly, on an electrode, or via the indirect reaction of the analyte with an electrochemically formed species which 'mediates' the destruction. The optical responses of these two reaction mechanisms are first predicted by numerical simulation followed by experimental validation of each using two fluorescent probes, a redox inactive (in the electrochemical window) 1,3,6,8-pyrenetetrasulfonic acid and the redox-active derivative 8-hydroxypyrene-1,3,6-trisulfonic acid. In the vicinity of a carbon electrode held at different oxidative potentials, the contrast between indirect electro-destruction, chlorination, and direct oxidation is very obvious. Excellent agreement is seen between the numerically predicted fluorescence intensity profiles and experiment.
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Affiliation(s)
- Junling Ma
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
| | - Minjun Yang
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
| | - Christopher Batchelor-McAuley
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
| | - Richard G Compton
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK.
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Vega Mercado F, Fernández R, Iglesias R, Dassie S. Facilitated proton transfer reactions via water autoprotolysis across oil|water interfaces. Spectroelectrochemical analysis. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.01.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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Molina A, Laborda E. Detailed theoretical treatment of homogeneous chemical reactions coupled to interfacial charge transfers. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.07.142] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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