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Mechanistic Study of the Activation and the Electrocatalytic Reduction of Hydrogen Peroxide by Cu-tmpa in Neutral Aqueous Solution.

ABSTRACT: Hydrogen peroxide plays an important role as an intermediate and product in the reduction of dioxygen by copper enzymes and mononuclear copper complexes. The copper(II) tris(2-pyridylmethyl)amine complex (Cu-tmpa) has been shown to produce H₂O₂ as an intermediate during the electrochemical 4-electron reduction of O₂. We investigated the electrochemical hydrogen peroxide reduction reaction (HPRR) by Cu-tmpa in a neutral aqueous solution. The catalytic rate constant of the reaction was shown to be one order of magnitude lower than the reduction of dioxygen. A significant solvent kinetic isotope effect (KIE) of 1.4 to 1.7 was determined for the reduction of H₂O₂, pointing to a Fenton-like reaction pathway as the likely catalytic mechanism, involving a single copper site that produces an intermediate copper(II) hydroxo species and a free hydroxyl radical anion in the process.

SUBMITTER: Langerman M

PROVIDER: S-EPMC8453753 | biostudies-literature |

REPOSITORIES: biostudies-literature

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