Cover Page
The following handle holds various files of this Leiden University dissertation:
http://hdl.handle.net/1887/59505
Author: Bremmer, G.M.
Title: Transmission electron microscopy on live catalysts
Issue Date: 2017-12-21
Transmission Electron Microscopy
on live catalysts
Transmission Electron Microscopy on live catalysts
Proefschrift ter verkrijging van
de graad van Doctor aan de Universiteit Leiden op gezag van Rector Magnificus prof. mr. C.J.J.M. Stolker
volgens besluit van het College voor Promoties te verdedigen op donderdag 21 december 2017
klokke 10:00 uur door
Gerrit Marinus Bremmer geboren te Katwijk aan Zee
in 1990
Promotor:
Prof. dr. J.W.M. Frenken Co-promotor:
Prof. dr. P.J. Kooyman
University of Cape Town, Kaapstad, Zuid-Afrika Promotiecommissie:
Prof. dr. E.J.M. Hensen
Technische Universiteit Eindhoven Prof. dr. P.E. de Jongh
Universiteit Utrecht Prof. dr. J. Aarts Prof. dr. E.R. Eliel Dr. I.M.N. Groot
ISBN: 978-90-8593-323-6 Casimir PhD series, Delft-Leiden 2017-39
The work in this thesis has been performed at the Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, Leiden, The Netherlands, and at the Zandbergen Lab, Department of Quantum Nanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands. The work has been financially supported by the Netherlands Organisation for Scientific Research (NWO/OCW), as part of the Frontiers of Nanoscience (NanoFront) program.
For a description of the cover illustration and all other illustrations in this PhD thesis, see Chapter ‘About the illustrations in this thesis’ on page 91.
I
Table of Contents
1. Introduction 1
1.1 Why is catalysis important? . . . .2
1.2 Research in catalysis, then and now . . . .2
1.3 TEM investigation on MoS2 catalysts . . . .4
1.4 In situ and operando TEM . . . .5
1.5 Operando TEM experiments of Co nanoparticles . . . .7
1.6 Developments of other in situ techniques . . . .8
2. Instability of NiMoS2 and CoMoS2 hydrodesulfurization catalysts at ambient conditions: A quasi in situ High-Resolution Transmission Electron Microscopy and X-Ray Photoelectron Spectroscopy study 15 2.1 Introduction . . . . 16
2.2 Experimental . . . . 16
2.2.1 Preparation of catalysts . . . . 16
2.2.2 Exposure to ambient air . . . . 17
2.2.3 Characterization of catalysts . . . . 17
2.3 Results and discussion . . . . 19
2.3.1 Imaging and slab length analysis . . . . 19
2.3.2 X-ray Photoelectron Spectroscopy . . . . 22
2.3.3 Proposed oxidation mechanism. . . . . 26
2.4 Conclusion . . . . 27
3. The effect of oxidation and resulfidation on (Ni/Co)MoS2 hydrodesulfurization catalysts 33 3.1 Introduction . . . . 34
3.2 Experimental . . . . 34
3.2.1 Preparation of catalysts . . . . 34
3.2.2 TEM and XPS characterization of catalysts . . . . 35
3.2.3 Catalytic activity . . . . 36
3.3 Results and discussion . . . . 37
3.3.1 Imaging and slab length analysis . . . . 37
3.3.2 Chemical state of the catalysts . . . . 39
3.3.3 Catalytic activity . . . . 42
3.3.4 Discussion . . . . 43
3.4 Conclusion . . . . 44
II
4. Cobalt-rhenium β-Mn-type bimetallic nanoparticles prepared via colloidal
chemistry 49
4.1 Introduction . . . . 50
4.2 Experimental . . . . 50
4.2.1 Synthesis of Co-Re nanoparticles . . . . 50
4.2.2 Nanoparticle characterization . . . . 51
4.3 Results and discussion . . . . 52
4.3.1 Characterization of Co-Re nanoparticles . . . . 52
4.3.2 Varying the Co-Re composition . . . . 55
4.3.3 High Re content . . . . 57
4.3.4 Thermal stability . . . . 58
4.4 Conclusion . . . . 58
5. In situ TEM observation of the Boudouard reaction: multi-layered graphene formation from CO on cobalt nanoparticles at atmospheric pressure 65 5.1 Introduction . . . . 66
5.2 Experimental . . . . 66
5.2.1 Cobalt nanoparticles . . . . 66
5.2.2 Nanoreactors . . . . 67
5.2.3 In situ TEM holder . . . . 67
5.2.4 Gas supply system and residual gas analysis . . . . 68
5.2.5 Transmission Electron Microscopy . . . . 69
5.3 Results and discussion . . . . 69
5.3.1 Nanoparticle preparation . . . . 69
5.3.2 Carbon deposition . . . . 71
5.3.3 Effect on the nanoparticles . . . . 75
5.3.4 Carbon morphologies . . . . 76
5.4 Conclusion . . . . 77
Summary 83
Samenvatting 87
About the illustrations in this thesis 91
Acknowledgements 93
Curriculum Vitae 95
List of Publications 97
III
IV
