MWW zeolites have three sets of pore systems: intralayer 10-membered ring (10MR) channels, 12-membered ring (12MR) supercages opened by the 10MR, and external surface 12MR cups (half of the supercage). It is this unique pore structure that allows MWW zeolites to exhibit excellent ethylbenzene selectivity and unique catalytic performance in ethylene-to-ethylbenzene alkylation reactions, as well as successful commercial applications [2].
MCM-22 zeolite catalysts demonstrate excellent selectivity and stability under low benzene-to-ethylene (B/E) ratios. At ethylene weight hourly space velocity (WHSV) of 0.7 h^(-1), the benzene-to-ethylene molar ratio (B/E) can be reduced to 2.0, with ethylbenzene selectivity reaching 84% and xylene content less than 50 mg/kg