Quantification of Bronsted acidity of rare earth exchanged (Ce³⁺, La³⁺, Sm³⁺and RE³⁺) NaFAU-Y zeolites in their Bronsted acid forms

Abstract

Thermodesorption of sterically hindered molecule such as 2,6- dimethyl pyridine (2 ,6-DMP) and cumene cracking test reactions have been applied to determine the nature of Bronsted acid sites (BAS) in pure H-Y, and various rare earth exchanged (Ce³⁺, La³⁺, Sm³⁺and RE³⁺) Na-Y zeolites. Incompatibility in<i> </i>the amount of 2.6-DMP desorbed is clearly an indication of the influence of the

nature of rare earth metal ions in producing BAS in zeolites. A one- to-one correlation has been observed between the amount of benzene formed during the catalytic cracking of cumene and Bronsted acidity measured by thermodesorption of the probe molecule.