Currently investigations into the catalytic and sorptive properties of layered structures such as cationic and anionic clays and zirconium phosphates. are hampered by a lack of understanding of the basic materials properties such as physical properties and their correlation to reactor performance and difficulties in scale-up. In addition, the exploitation of many of these materials has in the past been inhibited by their poor temperature stability. Recent advances suggest it may be possible to prepare materials which address high temperature applications.
This project has successfully developed processes for the reproducible and predictable preparation of pillared layered and multi-layered materials which have regular interlayer spacing and physical and chemical properties required for use in process chemistry and environmental applications. Three different types of pillared layered materials were studied: pillared layered clays, zirconium phosphates and phosphonates, and layered double hydroxides. Representative materials have been successfully scaled up to a semi-commercial scale, and the materials prepared were evaluated in a laboratory pilot scale plant for a range of reactions of commercial importance. Clay based catalysts performed well for the production of the gasoline additives such as methyltetrabutylether (MTBE), with the MTBE catalyst exhibiting a performance that was comparable to the current commercial catalyst. An aluminium pillared clay has proved active and selective for ethylene hydration and pillared clays have been shown to be highly suitable as catalysts for the synthesis of linear alkyl benzene. The zirconium phosphate dispersions in silica, functionalized with sulphonic acid groups, gave good results for the synthesis of MTBE. Also, these inorganic materials have shown useful activity towards ethylene hydration and the oxidative dehydrogenation of ethyl benzene. Chromium-copper based layered double hydroxides (LDH) pillared with vanadate or molybdate polyoxomettalate anions have been found to be very selective catalysts for the synthesis of glycol ethers.