Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 21, 1993 | public
Journal Article Open

Further studies on aluminophosphate molecular sieves. Part 2.—VPI-5 and related aluminophosphate materials

Abstract

VPI-5 and AlPO4-H2 are constructed from the same type of chain building unit which contains octahedral Al atoms (coordinated with four framework oxygens and two water molecules). The bonded water molecules are believed to stabilize the chain building unit and play an important role in the crystallization of these materials. This chain building unit limits the possibilities of incorporating silicon into the VPI-5 framework and synthesizing aluminosilicate or pure-silica versions of the VPI-5 structure. VPI-5 and AlPO4-H2 can irreversibly transform to AlPO4-8 and AlPO4-tridymite, respectively, via similar bond rearrangements. Several new aluminophosphates with X-ray powder diffraction reflections similar to some of those for VPI-5 are synthesized and their physicochemical properties do not match those for VPI-5. Strong evidence is provided to suggest that previous claims that VPI-5 and AlPO4-H1 are the same phase are unwarranted.

Additional Information

© Royal Society of Chemistry 1993 Paper 2/04620B; Received 27th August, 1992 Support of this work was provided by Akzo America, Inc. and the NSF Alan T. Waterman Award to M.E.D. We thank Dr. J. B. Higgins at Mobil Research and Development Corporation, Central Research Laboratory for helpful discussions. We acknowledge Dr. D. E. Cox for assistance in collecting the synchrotron data. The data were collected at X7A beam line, National Synchrotron Light Source, Brookhaven National Laboratory, which is supported by the US. Department of Energy, Division of Material Science and Division of Chemical Science.

Files

LIHjcsft93b.pdf
Files (1.0 MB)
Name Size Download all
md5:2346d56ba3abcc2b6b8b5066218bc37b
1.0 MB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 16, 2023