HIGH-RESOLUTION ELECTRON-MICROSCOPY CHARACTERIZATION OF SSZ-25 ZEOLITE

SSZ-25 has been known to have high catalytic activity, but no structur e has been reported. A combination of electron microscopy techniques w as employed to characterize this new zeolite. This allowed us to deter mine the unit cell and its relationship to the crystal morphology. The unit cell was hexagonal with a = 1.41 nm and c = 2.52 nm. The individ ual crystals tend to be thin flakes, and high-resolution electron micr oscopy (HREM) revealed that this zeolite has a multi-dimensional chann el system. The results of this work showed that there are large-pore z eolite channels arranged parallel to the c direction. The HREM results , when taken with other physical characterization methods, confirmed w hy this zeolite has high catalytic utility.