Steam and acid dealumination of mordenite

A systematic study of both acid and steam dealumination of mordenite has been carried out aiming to obtain a mordenite featuring high acid strength active sites along with a secondary mesoporous system, in order to maximize both catalytic performance and time-on-stream stability of the material in solid-acid catalyzed alkylation of benzene with 1-dodecene. Detailed assessment of the textural (XRD, N2 adsorption–desorption) and acid (FTIR of pyridine adsorption) properties of the obtained materials was performed. It has been found that catalysts obtained by combined steam dealumination and acid washing show a dramatic increase in the intrinsic activity and a significantly lower tendency to suffer deactivation when compared to the parent zeolite and samples obtained by acid treatments. This improved behaviour of the steam-treated sample is attributed to its increased mesoporous surface area, lower acid sites concentration and less hydrophilic surface.