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
Hierarchical MFI zeolite synthesized via regulating the kinetic of dissolution-recrystallization and their catalytic properties
Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
Number of Authors: 42018 (English)In: Catalysis communications, ISSN 1566-7367, E-ISSN 1873-3905, Vol. 115, p. 82-86Article in journal (Refereed) Published
Abstract [en]

Hierarchical MFI zeolites with open pores were synthesized by a temperature programmed dissolution-recrystallization post-treatment. By controlling the temperature of post-treatment using TPAOH, open macropores and mesopores were created by simply regulating the kinetics of dissolution and recrystallization. Benzyl alcohol self-etherification reaction, which only occurs in micropores, was tested on ZSM-5 to understand the effect of hierarchical pore system. The catalytic activity of hierarchical TS-1 was tested with cyclohexanone ammoximation. Hierarchical ZSM-5 and TS-1 zeolites with open pores showed higher catalytic activity compared with both hollow and conventional ones. The increased catalytic activities can be ascribed to the enhanced diffusion.

Place, publisher, year, edition, pages
2018. Vol. 115, p. 82-86
Keywords [en]
Hierarchical, Zeolite, MFI, Open pores, Catalytic performances
National Category
Chemical Sciences
Research subject
Inorganic Chemistry
Identifiers
URN: urn:nbn:se:su:diva-160248DOI: 10.1016/j.catcom.2018.07.006ISI: 000442190100018OAI: oai:DiVA.org:su-160248DiVA, id: diva2:1249667
Available from: 2018-09-20 Created: 2018-09-20 Last updated: 2019-02-13Bibliographically approved
In thesis
1. Synthesis, characterization and applications of hierarchical porous inorganic materials: a multi-dimensional approach
Open this publication in new window or tab >>Synthesis, characterization and applications of hierarchical porous inorganic materials: a multi-dimensional approach
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Zeolites are a type of microporous crystalline materials that have been widely used in industrial applications including separation, adsorption, and catalysis. However, great limitations on diffusion through these materials can arise due to the small pores present in mircoporous frameworks, and this can impact catalytic reactions in particular. The synthesis of hierarchical zeolites has solved the diffusion problem. In this thesis, various hierarchically porous materials have been synthesized and tested as catalysts.

In the first part of this thesis, a titanium-containing hierarchically porous silicate material has been constructed from double-four-ring (D4R) units as building blocks.

In the second part of this thesis, hierarchical MWW zeolites were synthesized by swelling and pillaring of a lamellar MWW zeolitic precursor (MCM-22) using D4R building units. The synthesis procedure has been carefully studied by various characterization methods, such as PXRD, TEM, N2 adsorption–desorption etc.

In the last part of this thesis, MFI zeolites with controllable hierarchical pore systems have been prepared. Firstly, hierarchical ZSM-5 and TS-1 with open pores were generated using a temperature programmed dissolution–recrystallization post-synthesis treatment and tested as catalysts for benzyl alcohol self-etherification and cyclohexanone ammoximation. Secondly, single-crystalline hierarchical shell-like ZSM-5 has been synthesized via a dissolution–recrystallization post-treatment of mesoporous ZSM-5. The post-treatment increased the catalytic activity of the ZSM-5 zeolite for the aldol condensation of bulky substrates.

Place, publisher, year, edition, pages
Stockholm: Department of Materials and Environmental Chemistry, Stockholm University, 2018. p. 96
Keywords
Zeolites, Porous material, Hierarchical, Synthesis, Catalysis, MFI zeolite, MWW zeolite, ZSM-5, TS-1
National Category
Chemical Sciences
Research subject
Inorganic Chemistry
Identifiers
urn:nbn:se:su:diva-159912 (URN)978-91-7797-444-4 (ISBN)978-91-7797-445-1 (ISBN)
Public defence
2018-10-24, Magnélisalen, Kemiska övningslaboratoriet Svante Arrhenius väg 16 B, Stockholm, 10:00 (English)
Opponent
Supervisors
Funder
Swedish Research Council
Note

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: Manuscript. Paper 4. Accepted.

Available from: 2018-10-01 Created: 2018-09-10 Last updated: 2018-09-25Bibliographically approved
2. 3D Electron Microscopy Methods and Applications: Structures from Atomic Scale to Mesoscale
Open this publication in new window or tab >>3D Electron Microscopy Methods and Applications: Structures from Atomic Scale to Mesoscale
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The crystal structure determines the physical properties of a material. The structure can be analysed at different levels, from atomic level, mesoscale level, all the way up to the macroscale level. Transmission Electron Microscope (TEM) is a powerful tool for studying the structure of materials at atomic scale level and mesoscale level because of the short wavelength of the electrons. At atomic scale level, structure determination using TEM can be performed in diffraction mode. The recent developments in 3D electron diffraction methods make structure determination from nano- and micron-sized crystals much easier than before. However, due to the strong interactions, electrons can be scattered multiple times through the crystal, causing the measured intensities to be less accurate than that in the X-ray case.

In this thesis, we use the continuous rotation electron diffraction (cRED) developed in our group to investigate the structure of materials and the accuracy of this method. In the third chapter, we use cRED method to determine the structure of two aluminophosphate zeolites, PST-13 and PST-14. We presented that these structures can be built from two pairs of enantiomeric structural building units. In the fourth chapter, we show that despite the inaccuracy in measured intensities originated from dynamical effect, it is still possible to determine the structure accurately. We show that the atomic coordinates of ZSM-5 and sucrose crystal structure determined by multiple electron diffraction datasets is identical to that determined from X-ray data or neutron data. We also assessed the linearity between calculated structure factor and observed structure factor and use this as a coarse assessment indicator for diffraction data quality for protein crystals.

Apart from atomic structure, mesoscale structures, such as mesopores, can also determine the property of materials. For the 3D structures of these nanoscale structures, we can also use TEM electron tomography techniques to investigate. In chapter five, we performed electron tomography for two different materials with mesoporous structure and illustrated the formation mechanism of mesoporous magnesium carbonate and the internal tunnel structure of hierarchical TS-1 zeolite.

Place, publisher, year, edition, pages
Stockholm: Department of Materials and Environmental Chemistry (MMK), Stockholm University, 2019. p. 58
Keywords
3D Electron microscopy, continuous rotation electron diffraction, structure determination, data quality, electron tomography, mesoporous materials, zeolites
National Category
Inorganic Chemistry
Research subject
Inorganic Chemistry
Identifiers
urn:nbn:se:su:diva-166070 (URN)978-91-7797-614-1 (ISBN)978-91-7797-615-8 (ISBN)
Public defence
2019-04-12, Magnélisalen, Kemiska övningslaboratoriet, Svante Arrhenius väg 16 B, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.

Available from: 2019-03-20 Created: 2019-02-13 Last updated: 2019-03-13Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full text

Search in DiVA

By author/editor
Lin, JunzhongYang, TaiminSun, Junliang
By organisation
Department of Materials and Environmental Chemistry (MMK)
In the same journal
Catalysis communications
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 17 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