Release Time:2019-06-25  Hits:

Indexed by: Journal Article

Date of Publication: 2018-06-29

Journal: iScience

Included Journals: PubMed

Volume: 4

Page Number: 144-152

ISSN: 2589-0042

Key Words: Electrocatalysis,Energy Materials,Inorganic Chemistry,Surface Science

Abstract: Identifying surface active intermediate species is essential to reveal the catalytic mechanism of water oxidation by metal-oxides-based catalysts and to develop more efficient catalysts for oxygen-oxygen bond formation. Here we report, through electrochemical methods and ex situ infrared spectroscopy, the identification of a MnVII = O intermediate during catalytic water oxidation by a c-disordered δ-MnOx with an onset-potential-dependent reduction peak at 0.93 V and an infrared peak at 912 cm-1. This intermediate is proved to be highly reactive and much more oxidative than permanganate ion. Therefore, we propose a new catalytic mechanism for water oxidation catalyzed by Mn oxides, with involvement of the MnVII = O intermediate in a resting state and the MnIV-O-MnVII = O as a real active species for oxygen-oxygen bond formation.Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.