Large (150 micron) crystals of HZSM-5 have been shown by electron microscopy, micro - XPS and selective dissolution experiments to be highly zoned, with an aluminium rich exterior and an aluminium deficient interior. The oligomerization of ethene in the crystals has been studied by C-13, NMR, FTIR microscopy and Raman microscopy. At low temperatures a largely linear oligomer is formed; above 200 degrees C chain branching occurs at channel intersections. Raman microspectroscopy can distinguish between oligomer in the interior and that near the outer surface of the crystals.
|Number of pages||8|
|Journal||Studies in Surface Science and Catalysis|
|Publication status||Published - 1994|