Figure 1. Correlative three-dimensional X-ray micro-spectroscopy.

(a) Hard X-rays emitted by two different insertion devices at the storage ring of the Stanford Synchrotron Radiation Lightsource (SSRL) were used for μ-XRF and nano-TXM tomography of an individual FCC catalyst particle that was loaded in a Kapton capillary with 200 μm inner diameter and 20 μm wall thickness. (b,c) In b, the 3D distributions of all elements in the FCC particle are presented that showed relevant count rates (intensities were corrected for self-absorption effects, see Supplementary Methods: correction of self-absorption effects in micro XRF tomography and Supplementary Fig. 4). These data were then used in the analysis of the spatial correlation of all elements of interest using Pearson's correlation coefficient (PCC) and the correlation plots reported in c. (d) High resolution TXM tomography data revealing the internal and external structure of the particle that is virtually cut open (see also Supplementary Movie 1). These data were then used in a pore throat analysis (e) applying a numerical solid expansion approach⁴⁵.