Toluene methylation over pillared clays with Al, Zr and Al/Zr oxides

Pillared clays (PILCs), with Al, Zr and Al/Zr oxides, obtained from a natural montmorillonite from Benavila (Portugal), were investigated in terms of their structure (XRD), texture (N 2 and toluene adsorption), acidity (pyridine chemisorption) and catalytic performances on methylation of toluene. Zr content reflects on the d 001 values and on the acidity of PILCs, that present, besides Lewis sites, also Bronsted acid sites. All the solids showed activity to toluene alkylation revealing that, even the Bronsted acidic properties that proceed only from the clay sheets are enough to promote alkylation. A mixture of xylenes (XY) was obtained as the main reaction products, and the isomers distribution followed generally the order m ≥ o > p . Trimethylbenzenes (TMB) and ethyltoluenes (EtT) were also found, and on all the samples the selectivities were S xy >> S TMB > S EtT .