ANILINE METHYLATION OVER AEL TYPE MOLECULAR-SIEVES

ALPO-11, SAPO-11 and MAPSO-11 were prepared hydrothermally. These micr oporous solid catalysts could be used for the synthesis of industriall y important N-alkylated products during aniline methylation. The activ ity of these catalysts was compared with aluminosilicates of high sili ca having Mm structure. A number of stronger acid sites enhance succes sive alkylation. Activity and selectivity of N,N-dialkylated product f or SAPO-11 is higher at all temperatures as compared to that of ALPO-1 1. By introduction of Mg in SAPO-11, during hydrothermal synthesis, a decrease in total acid strength and an increase in basic strength, as compared to SAPO-11, is observed. This acidity-basicity function is co rrelated with the activity of the catalyst and product pattern of the methylation of aniline. C-alkylated products via direct alkylation of aniline with methanol are not enhanced during the alkylation reaction, catalysed by ALPO-11 and its derivatives, whereas the reaction cataly sed by aluminosilicates and high silica aluminosilicates with MFI stru cture, some amount of C-alkylated products (toluidines) are formed.