Catalysis Letters, Vol.41, No.1-2, 13-16, 1996
A Quantitative Description of the Active-Sites in the Dehydrated Acid Catalyst Hsapo-34 for the Conversion of Methanol to Olefins
A neutron diffraction study of the deuterated form of a microcrystalline specimen of the H(+)SAPO-34 catalyst for converting methanol to light olefins reveals two distinct bridging hydroxyl Bronsted sites. These sites are also identified by IR spectroscopy which distinguishes their acid strength from the shift in O-H frequencies following adsorption of CO at 77 K. Protons attached to the O(4) bridging oxygen (OH distance 0.95 Angstrom) exhibit greater acidity than those attached to O(2) (OH distance 0.91 Angstrom).