Figure 8.

(a) Hypothetical changes in chemical potential, Δμ, with synthesis progress, adapted from the IZT concept proposed⁸ for different growth solutions (α and β) and zeolite products (FAU and GIS). Growth mixture α refers to the nominal synthesis condition resulting in a FAU-to-GIS transformation. Growth mixture β is the supernatant of the previous mixture extracted at a time corresponding to full FAU crystallinity prior to the onset of GIS nucleation, where continued heating results in direct crystallization of GIS. (b, c) Time-resolved powder XRD patterns of solids extracted from growth mixtures β (b) and α (c). Select peaks of FAU, GIS-P2, and impurity phases are indicated by green, purple, and orange circles, respectively. (d, e) Scanning electron micrographs of GIS-P2 products obtained after 7 days of hydrothermal treatment of growth mixtures (d) α and (e) β. Scale bars represent 1 μm.