A practical approach to the treatment of adsorption–desorption isotherms, acidity and catalytic behaviour of zeolite catalysts

✍ Scribed by Jana Horniakova; Milan Králik; Alexander Kaszonyi; Dušan Mravec

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 221 KB
• Volume: 46
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(01)00309-2

✦ Synopsis

The relationship between texture evaluated on the basis of nitrogen adsorption±desorption isotherms, acidity and catalytic activity of mordenite catalysts dealuminated to various extents and doped with cerium was investigated. The combination of the standard BET isotherm either with a consideration of the micropores, or with the Dubinin± Radushkevich isotherm proved to be a good tool for the estimation of the micropore volume and outer surface of the catalysts. A very good description of the surface of the micropores was obtained using the n-layer BET isotherm. SEM pictures of the catalysts revealed that the mesopores are probably located in the interparticle space between mordenite crystallites. The isopropylation of biphenyl was applied as a model reaction. Changes in the micro-and mesoporosity as well as changes in the acidity were invoked to account for the observed catalytic activities and selectivities for 4-isopropylbiphenyl and 4,4 H -diisopropylbiphenyl.