Multimodal Imaging of Autofluorescent Sites Reveals Varied Chemical Speciation in SSZ‐13 Crystals

Abstract

A multimodal imaging study of chabazite is used to show the distribution of and discriminate between different emissive deposits arising as a result of the detemplation process. Confocal imaging, 3D fluorescence lifetime imaging, 3D multispectral fluorescence imaging, and Raman mapping are used to show three different types of emissive behaviours each characterised by different spatial distributions, trends in lifetime, spectral signals, and Raman signatures. A notable difference is seen in the morphology of agglomerated surface deposits and larger subsurface deposits, which experience lifetime augmentation due to spatial confinement. The distribution of organic residue throughout the crystal volume is comparable to XRF mapping that shows Si enrichment on the outer edges and higher Al content through the centre, demonstrating that a fluorescence‐based technique can also be used to indirectly comment on the compositional chemistry of the inorganic framework.

Chemical Imaging of Hierarchical Porosity Formation within a Zeolite Crystal Visualized by Small‐Angle X‐Ray Scattering and In‐Situ Fluorescence Microscopy

“…Fluorescence microscopy visualizes hierarchical porosity via organic DAMPI stains residing in straight micropores of meso‐/macropore walls [21] . Complementary, SAXS microscopy can directly map and speciate the hierarchical pore properties of ZSM‐5 after desilication, allowing important multimodal imaging [23] (Figure 3 a). By xy‐raster scanning the zeolite ZSM‐5 crystal in roof view, a SAXS pattern is obtained for each xy‐pixel (500×500 nm 2 ) owing to e − ‐density differences in empty meso‐/macropore space and the zeolite framework.…”

Nickel Nanoparticles Encapsulated in SSZ-13 Cage for Highly Efficient CO2 Hydrogenation

“…SSZ-13, a porous crystalline chabazite, has been widely used in the catalysis field due to its particular structural and chemical properties. 35 SSZ-13 shows excellent hydrothermal stability under the harsh conditions 36 and also exhibits good affinity toward transition metal due to the H-form ionexchange site and charge-compensation effect. 37 Moreover, the cage constructed by the four-, six-, and eight-membered rings in the chabazite SSZ-13 has a highly selective CO 2 adsorption/ separation capacity.…”

“…SSZ-13, a porous crystalline chabazite, has been widely used in the catalysis field due to its particular structural and chemical properties . SSZ-13 shows excellent hydrothermal stability under the harsh conditions and also exhibits good affinity toward transition metal due to the H-form ion-exchange site and charge-compensation effect .…”

Chemical Imaging of Hierarchical Porosity Formation within a Zeolite Crystal Visualized by Small‐Angle X‐Ray Scattering and In‐Situ Fluorescence Microscopy

“…Fluorescence microscopy visualizes hierarchical porosity via organic DAMPI stains residing in straight micropores of meso-/macropore walls. [21] Complementary, SAXS microscopy can directly map and speciate the hierarchical pore properties of ZSM-5 after desilication, allowing important multimodal imaging [23] (Figure 3 a). By xy-raster scanning the zeolite ZSM-5 crystal in roof view, a SAXS pattern is obtained for each xy-pixel (500 500 nm 2 ) owing to e À -density differences in empty meso-/macropore space and the zeolite framework.…”