Preparation and characterisation of Zr, Ti and Zr-Ti mixed oxide pillared montmorillonite and their catalytic activity towards nitration of chlorobenzene

Abstract

Zr, Ti and Zr-Ti mixed oxide pillared montmorillonite (PILCs) have been prepared by standard method and their specific surface area, total acidity, and weight loss have been calculated. The mixed oxide pillared clays retain highest surface area even when calcined at 500degreesC. The total number of acid sites (mumol/g) are highest for 300degreesC calcined samples and follow the order Zr-Ti PILC > ZrPILC > TiPILC. Mononitration reaction is carried out using all the pillared montmorillonites calcined at different temperatures. The yield of mononitrochlorobenzene from chlorobenzene with different catalysts also follow the same order and no metaproduct has been detected for this reaction. All samples show appreciably high paraselectivity i.e. close to 85%.