Effect of acid treatments on physico-chemical properties and isomerization activity of mordenite

A series of mordenite-based catalysts of varying acidity and metal concentrations were prepared and the effect of physico-chemical properties of these catalysts on the n-hexane isomerization activity was studied. Acid treatment with nitric acid greatly influenced the nature and amount of aluminum in the zeolite characterized by 29Si and 27Al NMR. The microcalorimerty studies of ammonia adsorption clearly indicated the changes in density and strength of acid sites of mordenite upon acid treatment. At optimum conditions of acid treatment the catalyst exhibited improved properties such as acidity and the catalyst gave enthusiastic results claiming 98% selectivity to isomers in n-hexane hydroisomerization reaction. The catalyst and the reaction parameters for activity of Pt/H-mordenite have been discussed in the present paper.