Characterization of mordenites treated by HCl/steam or HF

✍ Scribed by Kyong-Hwan Lee; Baik-Hyon Ha

• Book ID: 104431495
• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 501 KB
• Volume: 23
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(98)00118-8

✦ Synopsis

Mordenites were modified by dealumination with HCl/steam or HF treatment, and characterized by X-ray fluorescence ( XRF ), X-ray photoelectron spectroscopy ( XPS), X-ray diffraction ( XRD), infrared spectroscopy, scanning electron microscopy (SEM ) and nitrogen adsorption. All mordenites retained more than 80% crystallinity, although the lattice parameters (a, b, c) were reduced more for HCl/steam-treated mordenites than for HF-treated mordenites. In the HCl/steam-treated mordenites, framework aluminum was mainly removed, while in the HF-treated mordenites, framework aluminum was removed extensively at the beginning of treatment, and thereafter silicon and aluminum were simultaneously removed. Mesopores with a diameter of 3.7 nm developed as a result of dealumination, which did not depend on the treatment methods. The acid strength was higher on the HCl/steam-treated mordenites than on the HF-treated mordenites.