Advanced microscope observes atomic-scale chemistry
11 July 2008 by TNWToday | M&CTU Delft researchers Dr Fredrik Creemer and Prof. Henny Zandbergen have developed a nanoreactor which enables chemical processes to be observed at nano level. This instrument opens up new opportunities for studying materials via microscopy. On 15 July, TU Delft is to hold a mini-symposium on nanoreactors and their applications.
Transmission electron microscopy (TEM) allows scientists to observe particles at atomic level. This equipment has one major drawback however: it works best in a high vacuum. Electrons crashing into other molecules would seriously distort the image. It is therefore not usually possible to observe chemical reactions using TEM.
Nanoreactor
Dr Fredrik Creemer has developed a new method which sidesteps this difficulty. Using this new method, only the very immediate area around the material under study is not in a vacuum. He places a tiny cover around the material, a nanoreactor, through which the beam of electrons from the microscope may pass, as may gases. Manufacturing technology from the microchip industry allows Creemer to make the nanoreactor extremely thin. There is a very low risk of electrons hitting a molecule when passing through and distorting the microscope image. In the nanoreactor it is therefore possible to conduct chemical reactions between a solid substance and gases and to observe this through the microscope at atomic level. The method is known as Environmental TEM (ETEM).
It is essential that the nanoreactor can withstand the temperatures and pressures which occur in many chemical reactions, as in the case of industrial reactors. The current nanoreactor can be heated to temperatures of five hundred degrees Celsius and can resist pressure of 1 standard atmosphere.
Among other things, the nanoreactor has been used to study the Cu/ZnO catalyst (used in the synthesis of methanol). The catalyst was exposed to hydrogen, whereby details measuring 0.18 nanometre could be observed.
Applied
ETEM opens up major opportunities for studying (the behaviour of) materials at nano level, for instance in the fields of catalysis, electrochemistry, materials science and biology. ETEM can already be applied in practice, for example by the Danish chemicals company Haldor Topsøe which recently joined the SmartMix Nano-Imaging under Industrial Conditions (NIMIC) research consortium.
Mini-symposium
On 15 July, a mini-symposium is being organised on the significance of and opportunities presented by nanoreactors in transmission electron microscopy. The mini-symposium will take place in Kronigzaal, Applied Sciences Faculty, Lorentzweg 1, 2628 CJ Delft, The Netherlands. Members of the press are welcome to attend, but please register in advance with Roel Kamerling: r.kamerling@tudelft.nl, +31 (0)15 2787993.
11.00
| Introduction to NIMIC by Prof. Joost Frenken (Scientific Director of NIMIC)
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11.15
| Dr Fredrik Creemer (TU Delft researcher): Atomic-scale electron microscopy at ambient pressure
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11.45
| Dr Alfons Molenbroek (R&D Division Haldor Topsøe): In situ characterisation of heterogeneous catalysts at Haldor Topsøe
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12.15
| Light lunch
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Note to the editor
For more information:
Dr Fredrik Creemer, Electrical Engineering, Mathematics and Computer Science Faculty, tel. +31 (0)15 2786277, E-mail J.F.Creemer@tudelft.nl
Prof. Henny Zandbergen, Applied Sciences Faculty, tel. +31 (0)15 2782266, E-mail H.W.Zandbergen@tudelft.nl
Creemer recently published an article on his research in the scientific journal Ultramicroscopy: doi 10.1016/j.ultramic.2008.04.014
