CONVERSION OF ANISOLE IN THE PRESENCE OF METHANOL OVER ALPO4-AL2O3 CATALYSTS MODIFIED WITH FLUORIDE AND SULFATE ANIONS

The gas-phase microcatalytic conversion of anisole in the presence of methanol (methanol/anisole molar ratio = 4) was studied at temperature s ranging from to 673 K over anion treated (1-3 wt.% F or SO42-) AlPO4 -Al2O3 (25 wt.% Al2O3) catalysts. Anisole conversion gave a mixture of dealkylated and C-alkylated products (C-alkylation preferentially in ortho-position) where dealkylation always predominates. The influences of the reaction temperature and both anion type and anion loading upo n the conversion of anisole and the selectivities of the products were investigated. The higher increase in surface acidity by fluoride load ing increases both the C-alkylation selectivity (mainly to 2-methylani sole) and dealkylation to phenol; so that a lower anisole conversion ( smaller pseudokinetic constant) and higher methylanisoles selectivity is found for APAI-P-F catalysts related to unmodified one.