Articles producció científica> Química Física i Inorgànica

Tetracobalt-polyoxometalate catalysts for water oxidation: Key mechanistic details

  • Identification data

    Identifier: imarina:3654742
  • Authors:

    Soriano-Lopez, Joaquin
    Musaev, Djamaladdin G.
    Hill, Craig L.
    Ramon Galan-Mascaros, Jose
    Carbo, Jorge J.
    Poblet, Josep M.
  • Others:

    Author, as appears in the article.: Soriano-Lopez, Joaquin; Musaev, Djamaladdin G.; Hill, Craig L.; Ramon Galan-Mascaros, Jose; Carbo, Jorge J.; Poblet, Josep M.;
    Department: Química Física i Inorgànica
    URV's Author/s: Carbó Martin, Jorge Juan / Poblet Rius, Josep Maria
    Keywords: Water oxidation catalysis Polyoxometalates Dft
    Abstract: A mechanism of water oxidation catalyzed by the carbon-free tetra-Co containing polyoxometalates [Co4(H2O)2(PW9O34)2]10¿ (PCo4) and [Co4(H2O)2(VW9O34)2]10¿ (VCo4) is elucidated by DFT calculations. Computational analysis for PCo4 suggests that a first PCET step may proceed via a sequential electron-then-proton transfer (ET + PT) pathway and leads to one electron oxidize species S1 (POM-CoIIIOH). In contrast, the second PCET, which controls the potential required to form POM-CoIIIO active species S2 is clearly a concerted process. The overall S0 ¿ S2 transformation is estimated to require less than 1.48 V and 1.62 V applied potential at pH = 8 for PCo4 and VCo4 anions, respectively. At operando conditions, with the presence of a buffer and with an applied potential above the threshold potential the two H-atom removal could take place via concerted pathways. These steps represent rapid pre-equilibria before the rate determining step, which corresponds to the OO bond formation. The key chemical step occurs via nucleophilic attack of an external water molecule to intermediate S2. We assume that this step governs the kinetics of the reaction. Comparison of the calculated energetics and electronic structures of intermediate species in the PCo4 and VCo4 catalyzed water oxidation cycle shows that coupling of d orbitals of V and Co atoms in VCo4 increases the oxidation potential of the Co-center. The orbital coupling is also responsible for the higher catalytic activity of VCo4 because it increases the electrophilicity of CoIIIO moiety in the key S2 species.
    Thematic Areas: Química Physical and theoretical chemistry Medicina i Materiais Interdisciplinar Engineering, chemical Engenharias iv Engenharias ii Ciências agrárias i Chemistry, physical Catalysis Astronomia / física
    licence for use: https://creativecommons.org/licenses/by/3.0/es/
    Author's mail: j.carbo@urv.cat josepmaria.poblet@urv.cat
    Author identifier: 0000-0002-3945-6721 0000-0002-4533-0623
    Record's date: 2023-10-21
    Papper version: info:eu-repo/semantics/acceptedVersion
    Link to the original source: https://www.sciencedirect.com/science/article/abs/pii/S0021951717301021
    Papper original source: Journal Of Catalysis. 350 56-63
    APA: Soriano-Lopez, Joaquin; Musaev, Djamaladdin G.; Hill, Craig L.; Ramon Galan-Mascaros, Jose; Carbo, Jorge J.; Poblet, Josep M.; (2017). Tetracobalt-polyoxometalate catalysts for water oxidation: Key mechanistic details. Journal Of Catalysis, 350(), 56-63. DOI: 10.1016/j.jcat.2017.03.018
    Licence document URL: http://repositori.urv.cat/ca/proteccio-de-dades/
    Article's DOI: 10.1016/j.jcat.2017.03.018
    Entity: Universitat Rovira i Virgili
    Journal publication year: 2017
    Publication Type: Journal Publications
  • Keywords:

    Catalysis,Chemistry, Physical,Engineering, Chemical,Physical and Theoretical Chemistry
    Water oxidation catalysis
    Polyoxometalates
    Dft
    Química
    Physical and theoretical chemistry
    Medicina i
    Materiais
    Interdisciplinar
    Engineering, chemical
    Engenharias iv
    Engenharias ii
    Ciências agrárias i
    Chemistry, physical
    Catalysis
    Astronomia / física
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