Cyclic Voltammetry Study of the Mn‐Substituted Polyoxoanions [MnII4(H2O)2(H4AsW15O56)2]18− and [((MnIIOH2)MnII2PW9O34)2(PW6O26)]17−: Electrodeposition of Manganese Oxides Electrocatalysts for Dioxygen Reduction

Abstract

AbstractThe electrochemical behavior of two manganese (Mn)‐substituted polyoxoanions, the dissymmetrical Dawson sandwich‐type [MnII4(H2O)2(H4AsW15O56)2]18− and the Keggin sandwich banana‐shaped [((MnIIOH2)MnII2PW9O34)2(PW6O26)]17− is investigated. At pH 5, the oxidation of the MnII‐centers results in one oxidation wave for [MnII4(H2O)2(H4AsW15O56)2]18− and two oxidation waves for [((MnIIOH2)MnII2PW9O34)2(PW6O26)]17−. To the best of our knowledge, presence of the second Mn‐based wave is rarely observed in the electrochemistry of Mn‐containing polyoxometalates. Deposition of Mn‐oxides electrocatalysts for dioxygen reduction is noticed by cyclic voltammetry, which can be distinguished by the significant positive shift in potentials of the dioxygen reduction reaction.