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Sparse X-ray transmission spectrotomography for nanoscopic compositional analysis of VPO catalysts

Zirui Gao & Manuel Guizar-Sicairos (SLS/PSI, CH)

June 22 at 10:00 am / 10:00 (CET)

The performance of functional materials is either driven or limited by nanoscopic heterogeneities distributed throughout the material’s volume. Recently, the combination of XANES spectroscopy and computed tomography imaging has emerged as a powerful tool for compositional analysis at nanoscopic level. However, these approaches are often hindered by the long acquisition time required by tomography sampling criteria at each energy. We introduce a method based on x-ray near-edge spectroscopy, ptychographic x-ray computed nanotomography, and sparsity techniques, which allows the acquisition of quantitative multimodal tomograms of representative sample volumes at sub–30 nm half-period spatial resolution while reducing the acquisition time almost 10 times compared to conventional methods. We investigated the transformation of vanadium phosphorus oxide catalysts with industrial use and observed changes that led to a reevaluation of these catalysts used in the production of plastics worldwide. Our work is published in Z. Gao, et al. « Sparse ab initio x-ray transmission spectrotomography for nanoscopic compositional analysis of functional materials. » Sci. Adv. 7, eabf6971 (2021).

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