European XFEL Science Seminar

In-situ and Multi-modal X-ray Microscopy of Heterogeneous Catalysts

by Florian Meirer (Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, The Netherlands)

E1.173 (Schenefeld) (European XFEL)

E1.173 (Schenefeld)

European XFEL

Modern X-ray imaging techniques allow for the combination of high spatial resolution, a large field of view, short dwell times, and the capability to obtain spectroscopic information. This has opened the door to high-resolution studies correlating chemistry and morphology of, for example, whole catalyst bodies. The relatively large penetration depth of X-rays furthermore allows for chemical imaging of catalysts ‘at work’, that is under operating conditions, which can involve high gas pressures (tens of bars) and temperatures (up to 1000 K). Here I will present two showcases for in-depth characterization of heterogeneous catalysts using X-ray microscopy (XRM) involving ex-situ and in-situ multi-modal approaches, respectively. The first covers studies of individual Fluid Catalytic Cracking (FCC) catalyst particles applying different synchrotron-based 2-D and 3-D XRM techniques (hard and soft X-rays) to understand catalyst deactivation ex-situ and at different length scales [1-7]. FCC is the main conversion technology in oil refinery for producing transportation fuels and chemical raw materials. The second showcase will cover results from hard and soft X-ray in-situ transmission XRM studying catalyst deactivation during Fischer-Tropsch synthesis (FTS) [8-11]. In FTS syngas is converted into different hydrocarbon chains by a catalytic surface polymerization reaction. FTS has experienced a renaissance as a result of higher environmental awareness, the ever-increasing worldwide demand for fuels, and a shift from fossil resources to more renewable resources. Here, a better understanding of the deactivation mechanisms requires in-situ spectro-microscopic measurements at relevant industrial conditions. References: [1] F. Meirer, S. Kalirai et al., Sci. Adv. 1, e1400199 (2015). [2] F. Meirer, D.T. Morris et al., J. Am. Chem. Soc. 137, 102–105 (2015). [3] F. Meirer et al., Chem. Commun. 51, 8097–8100 (2015). [4] S. Kalirai et al., ChemCatChem 7, 3674–3682 (2015). [5] A.M. Wise et al., ACS Catal. 6, 2178–2181 (2016). [6] S. Kalirai et al., Angew. Chem. Int. Ed. 55, 1–6 (2016). [7] Y. Liu, F. Meirer et al., Nat. Commun. 7, 12634 (2016). [8] I. Gonzalez-Jimenez et al., Angew. Chem. Int. Ed. 51, 11986–11990 (2012). [9] K.H. Cats et al., Chem. Commun. 49, 4622–4624 (2013). [10] K.H. Cats et al., Catal. Sci. Technol. 6, 4438–4449 (2016). [11] I.K. van Ravenhorst et al., in preparation (2017).