Origin of the heat-induced improvement of catalytic activity and stability of MnOx electrocatalysts for water oxidation

↓ Direkt till sidans innehåll
↓ Direkt till sidans sekundära innehåll (sidomenyn)

Search: onr:"swepub:oai:DiVA.org:uu-391360" > Origin of the heat-...

1 of 1
Previous record
Next record
To hitlist

Details
MARC

Abrashev, Miroslav V.Univ Sofia St Kliment Ohridski, Fac Phys, Sofia 1164, Bulgaria (author)

Origin of the heat-induced improvement of catalytic activity and stability of MnOx electrocatalysts for water oxidation

Article/chapterEnglish2019

Publisher, publication year, extent ...

2019
ROYAL SOC CHEMISTRY,2019
printrdacarrier

Numbers

LIBRIS-ID:oai:DiVA.org:uu-391360
https://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-391360URI
https://doi.org/10.1039/c9ta05108bDOI

Supplementary language notes

Language:English
Summary in:English

Part of subdatabase

SwePubSwePub

Classification

Subject category:ref swepub-contenttype
Subject category:art swepub-publicationtype

Notes

Catalysis of the oxygen evolution reaction (OER) by earth-abundant materials in the near-neutral pH regime is of great interest as it is the key reaction for non-fossil fuel production. To address the pertinent stability problems and insufficiently understood structure-activity relations, we investigate the influence of moderate annealing (100-300 degrees C for 20 min) for two types of electrodeposited Mn oxide films with contrasting properties. Upon annealing, the originally inactive and structurally well-ordered Oxide 1 of birnessite type became as OER active as the non-heated Oxide 2, which has a highly disordered atomic structure. Oxide 2 also improved its activity upon heating, but more important is the stability improvement: the operation time increased by about two orders of magnitude (in 0.1 M KPi at pH 7). Aiming at atomistic understanding, electrochemical methods including quantitative analysis of impedance spectra, X-ray spectroscopy (XANES and EXAFS), and adapted optical spectroscopies (infrared, UV-vis and Raman) identified structure-reactivity relations. Oxide structures featuring both di-mu-oxo bridged Mn ions and (close to) linear mono-mu-oxo Mn3+-O-Mn4+ connectivity seem to be a prerequisite for OER activity. The latter motif likely stabilizes Mn3+ ions at higher potentials and promotes electron/hole hopping, a feature related to electrical conductivity and reflected in the strongly accelerated rates of Mn oxidation and O-2 formation. Poor charge mobility, which may result from a low level of Mn3+ ions at high potentials, likely promotes inactivation after prolonged operation. Oxide structures related to the perovskite-like zeta-Mn2O3 were formed after the heating of Oxide 2 and could favour stabilization of Mn ions in oxidation states lower than +4. This rare phase was previously found only at high pressure (20 GPa) and temperature (1200 degrees C) and this is the first report where it was stable under ambient conditions.

Subject headings and genre

NATURVETENSKAP Kemi Materialkemi hsv//swe
NATURAL SCIENCES Chemical Sciences Materials Chemistry hsv//eng

Added entries (persons, corporate bodies, meetings, titles ...)

Chernev, PetkoUppsala universitet,Molekylär biomimetik,Free Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany(Swepub:uu)petch350 (author)
Kubella, PaulFree Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany (author)
Mohammadi, Mohammad RezaFree Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany;Univ Sistan & Baluchestan, Dept Phys, Zahedan 9816745845, Iran (author)
Pasquini, ChiaraFree Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany (author)
Dau, HolgerFree Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany (author)
Zaharieva, IvelinaFree Univ Berlin, Fachbereich Phys, Arnimallee 14, D-14195 Berlin, Germany (author)
Univ Sofia St Kliment Ohridski, Fac Phys, Sofia 1164, BulgariaMolekylär biomimetik (creator_code:org_t)

Related titles

In:Journal of Materials Chemistry A: ROYAL SOC CHEMISTRY7:28, s. 17022-170362050-74882050-7496

Internet link

Find in a library

Journal of Materials Chemistry A (Search for host publication in LIBRIS)

To the university's database

1 of 1
Previous record
Next record
To hitlist

Find more in SwePub

By the author/editor: Abrashev, Mirosl ...; Chernev, Petko; Kubella, Paul; Mohammadi, Moham ...; Pasquini, Chiara; Dau, Holger; show more...; Zaharieva, Iveli ...; show less...

About the subject

NATURAL SCIENCES: NATURAL SCIENCES; and Chemical Science ...; and Materials Chemis ...

Articles in the publication: Journal of Mater ...

By the university: Uppsala University

Search outside SwePub

Extend your search to:: Google; Google Book Search; Google Scholar

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

LIBRIS.kb.se