Genesis of Delaminated-Zeolite Morphology: 3-D Characterization of Changes by STEM Tomography.
Zeolite delamination increases the external surface area available for catalyzing the conversion of bulky molecules, but a fundamental understanding of the delamination process remains unknown. Here we report morphological changes accompanying delamination on the length scale of individual zeolite clusters determined by 3-D imaging in scanning transmission electron microscopy. The results are tomograms that demonstrate delamination as it proceeds on the nanoscale through two distinct key steps: a chemical treatment that leads to a swelled material and a subsequent calcination that leads to curling and peeling off of delaminated zeolite sheets over hundreds of nanometers. These results characterize the direct, local, 3-D morphological changes accompanying delaminated materials synthesis and, with corroboration by mercury porosimetry, provide unique insight into the morphology of these materials, which is difficult to obtain with any other technique.
†Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, United States.
Ilke
I
Arslan
‡Department of Chemical Engineering and Materials Science, University of California-Davis, One Shields Ave., Davis, California 95616, United States.
John D
JD
Roehling
§Department of Chemical and Biomolecular Engineering, University of California-Berkeley, Berkeley, California 94720, United States.
Isao
I
Ogino
K Joost
KJ
Batenburg
⊥Chevron Energy Technology Company, Richmond, California 94804, United States.
Stacey I
SI
Zones
‡Department of Chemical Engineering and Materials Science, University of California-Davis, One Shields Ave., Davis, California 95616, United States.
Bruce C
BC
Gates
§Department of Chemical and Biomolecular Engineering, University of California-Berkeley, Berkeley, California 94720, United States.
Alexander
A
Katz
3-D imaging; STEM; delamination; zeolites