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Chen W, Li H, Song J, Zhao Y, Ma P, Niu J, Wang J. Binuclear Ru(III)-Containing Polyoxometalate with Efficient Photocatalytic Activity for Oxidative Coupling of Amines to Imines. Inorg Chem 2022; 61:2076-2085. [PMID: 35025489 DOI: 10.1021/acs.inorgchem.1c03282] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel binuclear ruthenium-based polyoxometalate, K6H[{Ru2Cl(H2O)(CH3COO)2}{WO(H2O)}2(PW9O34)2]·14H2O (1), was successfully synthesized by the conventional hydrothermal method. Compound 1 was well-characterized by single-crystal X-ray diffraction, X-ray powder diffraction (PXRD), infrared (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), electrospray ionization-mass spectrometry (ESI-MS), thermogravimetric analyses (TGA), and elemental analysis. The structural unit of compound 1 contains two [A-α-PW9O34]9- building blocks at the upper and lower positions connected by two W atoms and two Ru atoms, where the W atoms and Ru atoms are arranged in a trapezoidal arrangement and the Ru atoms are bridged by acetic acid. Furthermore, compound 1 features characteristic absorption bands in the visible region, which allows the investigation of its photocatalytic properties in visible light. Under simulated sunlight radiation (λ > 400 nm), compound 1 exhibits high photocatalytic activity and good circularity toward the oxidative coupling of amines to imines at room temperature with O2 as the sole oxidant.
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Affiliation(s)
- Wenjing Chen
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, P. R. China
| | - Huafeng Li
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, P. R. China
| | - Junpeng Song
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, P. R. China
| | - Yujie Zhao
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, P. R. China
| | - Pengtao Ma
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, P. R. China
| | - Jingyang Niu
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, P. R. China
| | - Jingping Wang
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, Henan, P. R. China
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Cárdenas G, Trentin I, Schwiedrzik L, Hernández-Castillo D, Lowe GA, Kund J, Kranz C, Klingler S, Stach R, Mizaikoff B, Marquetand P, Nogueira JJ, Streb C, González L. Activation by oxidation and ligand exchange in a molecular manganese vanadium oxide water oxidation catalyst. Chem Sci 2021; 12:12918-12927. [PMID: 34745522 PMCID: PMC8513927 DOI: 10.1039/d1sc03239a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/30/2021] [Indexed: 11/21/2022] Open
Abstract
Despite their technological importance for water splitting, the reaction mechanisms of most water oxidation catalysts (WOCs) are poorly understood. This paper combines theoretical and experimental methods to reveal mechanistic insights into the reactivity of the highly active molecular manganese vanadium oxide WOC [Mn4V4O17(OAc)3]3- in aqueous acetonitrile solutions. Using density functional theory together with electrochemistry and IR-spectroscopy, we propose a sequential three-step activation mechanism including a one-electron oxidation of the catalyst from [Mn2 3+Mn2 4+] to [Mn3+Mn3 4+], acetate-to-water ligand exchange, and a second one-electron oxidation from [Mn3+Mn3 4+] to [Mn4 4+]. Analysis of several plausible ligand exchange pathways shows that nucleophilic attack of water molecules along the Jahn-Teller axis of the Mn3+ centers leads to significantly lower activation barriers compared with attack at Mn4+ centers. Deprotonation of one water ligand by the leaving acetate group leads to the formation of the activated species [Mn4V4O17(OAc)2(H2O)(OH)]- featuring one H2O and one OH ligand. Redox potentials based on the computed intermediates are in excellent agreement with electrochemical measurements at various solvent compositions. This intricate interplay between redox chemistry and ligand exchange controls the formation of the catalytically active species. These results provide key reactivity information essential to further study bio-inspired molecular WOCs and solid-state manganese oxide catalysts.
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Affiliation(s)
- Gustavo Cárdenas
- Institute of Theoretical Chemistry, University of Vienna Währinger Str. 17 1090 Vienna Austria
- Chemistry Department, Universidad Autónoma de Madrid Calle Francisco Tomás y Valiente, 7 28049 Madrid Spain
| | - Ivan Trentin
- Institute of Inorganic Chemistry I, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Ludwig Schwiedrzik
- Institute of Theoretical Chemistry, University of Vienna Währinger Str. 17 1090 Vienna Austria
| | | | - Grace A Lowe
- Institute of Inorganic Chemistry I, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Julian Kund
- Institute of Analytical and Bioanalytical Chemistry, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Christine Kranz
- Institute of Analytical and Bioanalytical Chemistry, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Sarah Klingler
- Institute of Analytical and Bioanalytical Chemistry, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Robert Stach
- Institute of Analytical and Bioanalytical Chemistry, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Boris Mizaikoff
- Institute of Analytical and Bioanalytical Chemistry, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Philipp Marquetand
- Institute of Theoretical Chemistry, University of Vienna Währinger Str. 17 1090 Vienna Austria
- IADCHEM, Institute for Advanced Research in Chemistry, Universidad Autónoma de Madrid Madrid Spain
| | - Juan J Nogueira
- Chemistry Department, Universidad Autónoma de Madrid Calle Francisco Tomás y Valiente, 7 28049 Madrid Spain
- IADCHEM, Institute for Advanced Research in Chemistry, Universidad Autónoma de Madrid Madrid Spain
| | - Carsten Streb
- Institute of Inorganic Chemistry I, Ulm University Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Leticia González
- Institute of Theoretical Chemistry, University of Vienna Währinger Str. 17 1090 Vienna Austria
- Vienna Research Platform on Accelerating Reaction Discovery, University of Vienna Währinger Str. 17 1090 Vienna Austria
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Zou Y, Li H, Zhao X, Song J, Wang Y, Ma P, Niu J, Wang J. Ru(III) -based polyoxometalate tetramers as highly efficient heterogeneous catalysts for alcohol oxidation reactions at room temperature. Dalton Trans 2021; 50:12664-12673. [PMID: 34545885 DOI: 10.1039/d1dt01819a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel ruthenium-containing polyoxometalate-based organic-inorganic hybrid, K4Na9H7.4[(AsW9O33)4(WO2)4{Ru3.2(C3H3N2)2}]·42H2O (1), was successfully synthesized by a one-step hydrothermal method under acidic conditions, which applied a self-assembly strategy between inorganic polyoxometalate based on trivacant [B-α-AsW9O33]9- {AsW9} fragments and an organic ligand, imidazole (C3H4N2). Compound 1 was further characterized by single-crystal X-ray diffraction, PXRD, IR spectroscopy, UV-Vis spectroscopy, ESI-MS, elemental analysis and TGA. Single-crystal X-ray diffraction data reveal that the polyanion consists of four trivacant Keggin-type polyanion {AsW9} building blocks bridged by four {WO6} units, leading to a crown-shaped tetrameric structure [(AsW9O33)4(WO2)4{Ru3.2(C3H3N2)2}]20.4-. The ESI-MS result reveals that the polyanion unit has excellent structural integrity in water. Moreover, the catalysis study of 1 was also further investigated, and the experimental results indicate heterogeneous catalyst 1 presents high efficiency (yield = 98%), excellent selectivity (>99%), and good recyclability for the oxidation of 1-(4-chlorophenyl)ethanol to 4'-chloroacetophenone with commercially available 70% aqueous tert-butyl hydroperoxide {TBHP (aq.)} as the oxidant at room temperature.
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Affiliation(s)
- Yan Zou
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng Henan 475004, P.R. China.
| | - Huafeng Li
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng Henan 475004, P.R. China.
| | - Xue Zhao
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng Henan 475004, P.R. China.
| | - Junpeng Song
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng Henan 475004, P.R. China.
| | - Yaqiong Wang
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng Henan 475004, P.R. China.
| | - Pengtao Ma
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng Henan 475004, P.R. China.
| | - Jingyang Niu
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng Henan 475004, P.R. China.
| | - Jingping Wang
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng Henan 475004, P.R. China.
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Aspera SM, Arevalo RL, Nakanishi H, Kasai H, Sekine S, Kawai H. Vanadium doped polyoxometalate: induced active sites and increased hydrogen adsorption. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:195001. [PMID: 31945756 DOI: 10.1088/1361-648x/ab6cc3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We analyzed the electronic and structural properties of an α-Keggin type molybdenum-based polyoxometalate (POM) [[PMo12O40]3-] and its capacity for reduction reaction via H adsorption using ab initio calculations based on density functional theory (DFT). We also determined the change in the electronic properties brought about by vanadium substitutional doping, and its effect on the capacity of POM to adsorb H atom. We found that the optimal substitutional doping of four vanadium per one unit of POM is adequate to maintain its structural stability. Furthermore, increasing dopant concentration changes charge redistribution such that it induces charge transfer to an initially less active sites for H adsorption on pristine POM. This may increase the possibility of creating active sites from an initially inert H adsorption sites and allows for a higher density of H adsorption. This phenomenon could be relevant for chemical reactions that initially requires high number of pre-adsorbed H atoms.
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Affiliation(s)
- Susan Meñez Aspera
- National Institute of Technology, Akashi College, 679-3 Nishioka, Uozumi, Akashi, Hyogo 674-8501, Japan
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The Reactivity and Stability of Polyoxometalate Water Oxidation Electrocatalysts. Molecules 2019; 25:molecules25010157. [PMID: 31906045 PMCID: PMC6983101 DOI: 10.3390/molecules25010157] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/20/2019] [Accepted: 12/27/2019] [Indexed: 01/08/2023] Open
Abstract
This review describes major advances in the use of functionalized molecular metal oxides (polyoxometalates, POMs) as water oxidation catalysts under electrochemical conditions. The fundamentals of POM-based water oxidation are described, together with a brief overview of general approaches to designing POM water oxidation catalysts. Next, the use of POMs for homogeneous, solution-phase water oxidation is described together with a summary of theoretical studies shedding light on the POM-WOC mechanism. This is followed by a discussion of heterogenization of POMs on electrically conductive substrates for technologically more relevant application studies. The stability of POM water oxidation catalysts is discussed, using select examples where detailed data is already available. The review finishes with an outlook on future perspectives and emerging themes in electrocatalytic polyoxometalate-based water oxidation research.
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Craig MJ, Coulter G, Dolan E, Soriano-López J, Mates-Torres E, Schmitt W, García-Melchor M. Universal scaling relations for the rational design of molecular water oxidation catalysts with near-zero overpotential. Nat Commun 2019; 10:4993. [PMID: 31704927 PMCID: PMC6841662 DOI: 10.1038/s41467-019-12994-w] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/03/2019] [Indexed: 11/09/2022] Open
Abstract
A major roadblock in realizing large-scale production of hydrogen via electrochemical water splitting is the cost and inefficiency of current catalysts for the oxygen evolution reaction (OER). Computational research has driven important developments in understanding and designing heterogeneous OER catalysts using linear scaling relationships derived from computed binding energies. Herein, we interrogate 17 of the most active molecular OER catalysts, based on different transition metals (Ru, Mn, Fe, Co, Ni, and Cu), and show they obey similar scaling relations to those established for heterogeneous systems. However, we find that the conventional OER descriptor underestimates the activity for very active OER complexes as the standard approach neglects a crucial one-electron oxidation that many molecular catalysts undergo prior to O-O bond formation. Importantly, this additional step allows certain molecular catalysts to circumvent the "overpotential wall", leading to enhanced performance. With this knowledge, we establish fundamental principles for the design of ideal molecular OER catalysts.
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Affiliation(s)
- Michael John Craig
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin, 2, Ireland
| | - Gabriel Coulter
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin, 2, Ireland
| | - Eoin Dolan
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin, 2, Ireland
| | - Joaquín Soriano-López
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin, 2, Ireland
| | - Eric Mates-Torres
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin, 2, Ireland
| | - Wolfgang Schmitt
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin, 2, Ireland
| | - Max García-Melchor
- School of Chemistry, CRANN and AMBER Research Centres, Trinity College Dublin, College Green, Dublin, 2, Ireland.
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Soriano-López J, Musaev DG, Hill CL, Galán-Mascarós JR, Carbó JJ, Poblet JM. Tetracobalt-polyoxometalate catalysts for water oxidation: Key mechanistic details. J Catal 2017. [DOI: 10.1016/j.jcat.2017.03.018] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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