Transmission electron microscopy study of zeolite TPA/ZSM-5 using a slow-scan CCD camera

Studies of high-resolution transmission electron microscopy and selected area electron diffraction are made to investigate a structure of zeolite ZSM-5 containing organic ions TPA+ (tetrapropylammonium). A slow-scan CCD camera attached to a 400 kV electron microscope is used for the observation in order to make a quantitative analysis of image and diffraction patterns, and to minimize the irradiation damage of the zeolite and confined organic ions. A distribution of dark contrast attributed to the presence of TPA+ ions is indicated in the observed high-resolution image, as well as in the image processed for contrast enhancement. A Fourier synthesis is made by using observed diffraction intensities along with phases calculated from a structure model. The obtained Fourier map clearly showed an existence of TPA+ ions, of which concentration is approximately half of that previously reported by an X-ray diffraction study.