Characterizing non-zeolitic pore volume in zeolite membranes by temperature-programmed desorption

✍ Scribed by Miao Yu; John L. Falconer; Richard D. Noble

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 157 KB
• Volume: 113
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/j.micromeso.2007.11.021

✦ Synopsis

Temperature-programmed desorption is shown to be an effective method to measure the volume of non-zeolitic pores in a MFI membrane. A molecule that was too large to adsorb into the MFI pores at room temperature and the experimental time scale, 2,2-dimethylbutane, was adsorbed in the non-zeolitic pores, and its liquid density was used to estimate their pore volume. When n-hexane or n-octane adsorbed in the MFI pores, the non-zeolitic pore volume decreased by 55%, whereas benzene adsorbed in the MFI pores had no effect. The non-zeolitic pore volume decreased because n-hexane and n-octane swell the MFI crystals of the membrane and decrease the nonzeolitic pore size (the space between the MFI crystals), but benzene does not.