Surface characteristics and cracking activity of zirconium pillared clays

Abstract

Zirconium pillared montmorillonite and vermiculite catalysts have been prepared using four different methods by intercalation with zirconium oxychloride solution. The surface characteristics of the catalysts have been characterized using nitrogen

<span style="font-size:12.0pt;font-family:" times="" new="" roman";="" mso-fareast-font-family:"times="" roman";mso-ansi-language:en-in;mso-fareast-language:="" en-in;mso-bidi-language:ar-sa"="" lang="EN-IN">adsorption, XRD and IR studies. The nature of acid site is identified on the basis of IR spectral data of pyridine and ammonia adsorbed zirconium pillared catalysts. The acidity of the samples was determined by butylamine titration as well as by thermal desorption of pyridine and ammonia. Differential scanning calorimetric technique has also been used to probe the nature of acidic sites, their heterogeneity, acid strength and density. Cumene cracking has been carried out as a test reaction of Bronsted acidity. The product selectivity is towards benzene. The cracking activity has been correlated with the density of Bronsted acid sites.</span>