A suite of recently developed chemical tomography techniques are now available for users on the Microfocus Spectroscopy beamline I18. These allow users to observe the location and chemical structure of catalysts during operation in both gas and liquid phase.
Identifying the active site of a catalyst under operating conditions is one of the holy grails of catalysis research. Locating the different structures is important as catalysts can have the same chemical composition but be deposited on a support in a variety of different ways, leading to changes in how active/selective the catalyst is. By being able to identify the spatial distribution, and correlate it with the activity/selectivity we can help to design better, more efficient catalysts.
a) Custom-made micro reactor designed for acquiring the chemical tomography measurements; b) XRF-CT reconstruction of a liquid phase hydrogenation catalyst with Pt (red) mainly on the support surface, and Mo (green) distributed within the support pore structure.
Dr Stephen Price, PDRA on I18, who pioneered the use of the technique at Diamond along with Professor Andy Beale from UCL, said: “We are developing the imaging capabilities with a focus on catalytic systems since catalysis is one of the most important chemical industries in the world. Currently we are developing a high pressure reactor to image Fischer Tropsch catalysis – the conversion of CO and H2 to short chain hydrocarbons (i.e. clean synthetic petrol). However the techniques can be applied to many other fields such as biological and materials sciences, or even cultural heritage.”
The techniques allow for the location of the elements present in a sample to be identified with a resolution of less than 2 μm. Further to this, the short and long range order of the elements can be identified, allowing the location of different chemical structures to be mapped within a sample. To discuss potential applications, contact I18’s Principal Beamline Scientist Fred Mosselmans: firstname.lastname@example.org.
Dr Stephen Price, PDRA on I18, with data from recent chemical tomography experiments.
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