The University of Southampton
University of Southampton Institutional Repository

In situ spectroscopic investigations of MoOx/Fe2O3 catalysts for the selective oxidation of methanol

In situ spectroscopic investigations of MoOx/Fe2O3 catalysts for the selective oxidation of methanol
In situ spectroscopic investigations of MoOx/Fe2O3 catalysts for the selective oxidation of methanol
Multicomponent oxide shell@core catalysts have been prepared, affording overlayers of MoOx on Fe2O3. This design approach allows bulk characterization techniques, such as X-ray Absorption Fine Structure (XAFS), to provide surface sensitive information. Coupling this approach with in situ methodologies provides insights during crucial catalytic processes. Calcination studies were followed by a combination of XAFS and Raman, and demonstrate that amorphous multi-layers of MoOx are first converted to MoO3 before formation of Fe2(MoO4)3. However, a single overlayer of Oh Mo units remains at the surface at all times. In situ catalysis studies during formaldehyde production identified that Mo6+ was present throughout, confirming that gas phase oxygen transfer to molybdenum is rapid under reaction conditions. Reduction studies in the presence of MeOH resulted in the formation of reduced Mo–Mo clusters with a bonding distance of 2.6 Å. It is proposed that the presence of the clusters indicates that the selective conversion of MeOH to formaldehyde requires multiple Mo sites
2044-4753
722-730
Brookes, C.
485540de-a96e-4c26-9324-291b8cdcc80f
Bowker, M.
8e99ffe0-6f5e-442e-a30a-158afaa3f85c
Gibson, Emma K.
fc35e40a-278f-420c-88e7-9a05b98d393d
Gianolio, D.
147e5c5f-f2de-458e-b977-ab706cba9363
Mohammed, K. M. H.
1c3c5641-4d0a-4c4d-bb26-fe733b8dbf63
Parry, S.
a54916d3-adda-4d4b-a5ec-b3712ff7836f
Rogers, S. M.
50439b03-5c46-402c-be9b-6b69ab9be63e
Silverwood, I. P.
82866f8b-db54-4b52-ae0e-20ac70e21b9e
Wells, P. P.
bc4fdc2d-a490-41bf-86cc-400edecf2266
Brookes, C.
485540de-a96e-4c26-9324-291b8cdcc80f
Bowker, M.
8e99ffe0-6f5e-442e-a30a-158afaa3f85c
Gibson, Emma K.
fc35e40a-278f-420c-88e7-9a05b98d393d
Gianolio, D.
147e5c5f-f2de-458e-b977-ab706cba9363
Mohammed, K. M. H.
1c3c5641-4d0a-4c4d-bb26-fe733b8dbf63
Parry, S.
a54916d3-adda-4d4b-a5ec-b3712ff7836f
Rogers, S. M.
50439b03-5c46-402c-be9b-6b69ab9be63e
Silverwood, I. P.
82866f8b-db54-4b52-ae0e-20ac70e21b9e
Wells, P. P.
bc4fdc2d-a490-41bf-86cc-400edecf2266

Brookes, C., Bowker, M., Gibson, Emma K., Gianolio, D., Mohammed, K. M. H., Parry, S., Rogers, S. M., Silverwood, I. P. and Wells, P. P. (2016) In situ spectroscopic investigations of MoOx/Fe2O3 catalysts for the selective oxidation of methanol. Catalysis Science & Technology, 6 (3), 722-730. (doi:10.1039/c5cy01175b).

Record type: Article

Abstract

Multicomponent oxide shell@core catalysts have been prepared, affording overlayers of MoOx on Fe2O3. This design approach allows bulk characterization techniques, such as X-ray Absorption Fine Structure (XAFS), to provide surface sensitive information. Coupling this approach with in situ methodologies provides insights during crucial catalytic processes. Calcination studies were followed by a combination of XAFS and Raman, and demonstrate that amorphous multi-layers of MoOx are first converted to MoO3 before formation of Fe2(MoO4)3. However, a single overlayer of Oh Mo units remains at the surface at all times. In situ catalysis studies during formaldehyde production identified that Mo6+ was present throughout, confirming that gas phase oxygen transfer to molybdenum is rapid under reaction conditions. Reduction studies in the presence of MeOH resulted in the formation of reduced Mo–Mo clusters with a bonding distance of 2.6 Å. It is proposed that the presence of the clusters indicates that the selective conversion of MeOH to formaldehyde requires multiple Mo sites

Text
c5cy01175b.pdf - Version of Record
Available under License Other.
Download (2MB)
Text
c5cy01175b.pdf - Other
Available under License Creative Commons Attribution.
Download (2MB)

More information

Accepted/In Press date: 21 August 2015
Published date: 7 February 2016
Organisations: Organic Chemistry: SCF

Identifiers

Local EPrints ID: 400532
URI: http://eprints.soton.ac.uk/id/eprint/400532
ISSN: 2044-4753
PURE UUID: 3e60cbf1-99c9-4a2f-bbf4-8be3d2a2c290
ORCID for K. M. H. Mohammed: ORCID iD orcid.org/0000-0002-9538-0936
ORCID for P. P. Wells: ORCID iD orcid.org/0000-0002-0859-9172

Catalogue record

Date deposited: 16 Sep 2016 15:33
Last modified: 25 Feb 2020 01:45

Export record

Altmetrics

Contributors

Author: C. Brookes
Author: M. Bowker
Author: Emma K. Gibson
Author: D. Gianolio
Author: S. Parry
Author: S. M. Rogers
Author: I. P. Silverwood
Author: P. P. Wells ORCID iD

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×