Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Performance of a biomimetic oxidation catalyst immobilized on silica particles
Stockholm University, Faculty of Science, Department of Organic Chemistry.
Stockholm University, Faculty of Science, Department of Organic Chemistry.
Show others and affiliations
2013 (English)In: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 303, 16-21 p.Article in journal (Refereed) Published
Abstract [en]

A biomimetic oxidation catalyst, cobalt porphyrin with thiol linkers, was chemically conjugated to silica particles and utilized in the oxidation of hydroquinone to benzoquinone. The cobalt porphyrin/silica particle catalyst was characterized with Inductively Coupled Plasma (ICP) and X-ray Photoelectron Spectroscopy (XPS). The catalytic performance of the cobalt porphyrin molecules was compared to previous results for the same catalyst grafted to a gold surface and on silicon wafers. The measured catalytic activity, after background correction, was 100 times higher than that of its homogeneous counterpart, 10 times higher than that on a silicon wafer, and almost the same as that on a gold surface. The turnover frequency rates after 400 h are still comparable with initial rates reported for homogeneous porphyrins and salophens, whereas the use of particles as support increases the active surface area, which removes the limitations for scale-up associated with the previously used silicon wafers and gold surfaces.

Place, publisher, year, edition, pages
2013. Vol. 303, 16-21 p.
Keyword [en]
Biomimetic, Catalysis, Cobalt porphyrin, Immobilization, Silica particles, X-ray Photoelectron Spectroscopy, Magnetic particles, Turnover number, Turnover frequency
National Category
Organic Chemistry
Research subject
Organic Chemistry
Identifiers
URN: urn:nbn:se:su:diva-92259DOI: 10.1016/j.jcat.2013.03.008ISI: 000320216600003OAI: oai:DiVA.org:su-92259DiVA: diva2:638073
Funder
EU, European Research Council, AdG 247014Berzelii Centre EXSELENTSwedish Research Council
Note

AuthorCount:5;

Available from: 2013-07-25 Created: 2013-07-25 Last updated: 2017-10-11Bibliographically approved
In thesis
1. Development and Applications of Surface-Confined Transition Metal Complexes: Heterogeneous Catalysis and Anisotropic Particle Surfaces
Open this publication in new window or tab >>Development and Applications of Surface-Confined Transition Metal Complexes: Heterogeneous Catalysis and Anisotropic Particle Surfaces
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The main focus of this thesis has been directed towards developing novel surface-confined transition metal complexes for applications in heterogeneous catalysis and for the preparation of anisotropic particle surfaces. The first part describes the heterogenization of a homogeneous transition metal-based catalyst tetraphenyl cobalt porphyrin (CoTPP) on silicon wafers and on silica particles. The activity in hydroquinone oxidation for the silica particle-immobilized CoTPPs was found to be increased 100-fold compared to its homogeneous congener whereas the silicon wafer-immobilized CoTPPs achieved lower activity due to the formation of clusters of catalyst molecules on the support surface as detected with atomic force microscopy (AFM). The second part of this thesis describes the development and characterization of anisotropic particle-surfaces by electrochemical site-specific oxidation of surface-confined thiols. Reactive patches or gold gradients could be obtained on the particle surfaces depending on the type of working electrode used and on the electrolyte composition. The particle surface functionalities were characterized with X-ray photoelectron spectroscopy (XPS) and the particle-surface-confined patches and gradients were conjugated with proteins to obtain fluorescence for investigation using fluorescence microscopy. Gold-functionalized siliceous mesocellular foams were further demonstrated to be highly efficient and selective catalysts in the cycloisomerization of 4-alkynoic acids to lactones. The final part of this thesis describes the preparation and characterization of palladium nanoparticles heterogenized in the pores of siliceous mesocellular foam. The nanoparticles were analyzed with transmission electron microscopy (TEM) and found to have a size of 1-2 nm. Primary- and secondary benzylic- and allylic alcohols were oxidized by the heterogeneous palladium nanoparticles in high to excellent yields using air atmosphere as the oxygen source. The nanopalladium catalyst was used up to five times without any decrease in activity and the size of the nanoparticles was retained according to TEM.

Place, publisher, year, edition, pages
Stockholm: Department of Organic Chemistry, Stockholm University, 2013. 93 p.
Keyword
heterogeneous catalysis, anisotropic particles, protein gradients, nanoparticles
National Category
Chemical Sciences
Research subject
Organic Chemistry
Identifiers
urn:nbn:se:su:diva-88215 (URN)978-91-7447-656-9 (ISBN)
Public defence
2013-04-18, Magnelisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 16 B, Stockholm, 13:00 (English)
Opponent
Supervisors
Note

At the time of doctoral defence the following paper were unpublished and had a status as follows: Paper1: Manuscript; Paper 4: Manuscript

Available from: 2013-03-26 Created: 2013-03-11 Last updated: 2017-10-11Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Eriksson, KristoferBäckvall, Jan-E.
By organisation
Department of Organic Chemistry
In the same journal
Journal of Catalysis
Organic Chemistry

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 58 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf