Influence of rare earth elements La, Nd and Yb on the acidity of H-MCM-22 and H-Beta zeolites

The n-heptane cracking reaction shows that the effect of rare earth elements is related not only to the acidity but also with the porous structure of both zeolites. In H-Beta zeolite, the presence of RE elements enhances the acidity of the catalysts. In H-MCM-22 zeolite, the most relevant effect of rare earth elements is on the shape selectivity that becomes more pronounced with the ionic radius of the RE elements. The nature of the coke deposited on the two materials shows distinct profiles that are also related to its porous structure.