returned to Earth at the conclusion of Expedition 6 and sent back to the principal investigator
for analysis.
Results from the samples mixed on ISS suggest that the Lewis acid catalytic sites are altered in
microgravity, as indicated by lower catalytic activity in the MPV probe reaction compared to
Earth-grown zeolite. This further suggests that the control of fluid dynamics during
crystallization may be important in making better industrial catalysts. Although space-grown
zeolites had the same particle morphology and identical surface framework as zeolites grown
on Earth, the average zeolite size of the space-grown crystals was 10% larger than crystals
grown on Earth (Akata 2004).
Larger zeolite crystals allow researchers to better define the structure and understand how
they work, with a goal of producing improved crystals on Earth. Improved zeolites may have
applications in storing hydrogen fuel, reduction of hazardous byproducts from chemical
processing, and more efficient techniques for petroleum processing (Akata 2009).
PUBLICATION(S)
Akata B, Goodrich TL, Ziemer KS, Sacco, Jr A. The catalytic activity of space versus terrestrial
synthesized zeolite Beta catalysts in the Meerwein Ponndorf Verley Reactions: Support for PFAL
as the Lewis active site for cis-alcohol selectivity. Microgravity Science and Technology. June
2007;19(2):5-11. doi: 10.1007/BF02911862.
Akata B, Yilmaz B, Jirapongphan SS, Warzywoda J, Sacco Jr A. Characterization of zeolite Beta
grown in microgravity. Microporous and Mesoporous Materials. June 2004;71(1-3):1-9. doi:
10.1016/j.micromeso.2004.03.012.
This investigation is complete, and all results are published.