Influencing the activity and selectivity of alkylaromatic catalytic transformations by varying the degree of delamination in MWW zeolites

Abstract

The degree of delamination and chemical composition of MWW zeolites have been varied by adjusting the synthesis parameters and modifying the temperature of the swelling step applied to the layered precursor (MCM-22(P)), and their impact on the catalytic behavior of these MWW materials for alkylaromatic transformation reactions has been studied. Kinetic experiments performed in a fluidized-type riser simulator have allowed us to establish a complete reaction network and to discern the impact of the catalyst's variables on competing alkylation and transalkylation of alkylbenzene molecules. In this way, the positive effect of delamination of the MWW layered precursor regarding the selectivity for the alkylation product with respect to transalkylation and catalyst deactivation has been confirmed by comparing a microporous MCM-22 with a highly delaminated ITQ-2 obtained from the same layered precursor, and also for 3D MCM-22 and highly delaminated ITQ-2 with comparable acidic properties.