Facile Synthesis of Two-Dimensional MWW Zeolites with Vapor-Phase Pillarization Strategy for Alkylation of Benzene and 1-Dodecene

The production of linear alkylbenzene (LAB) by alkylation of benzene with 1-dodecene over zeolite catalysts always imposes serious diffusion limitations, while pillarization is an essential way for fabrication of ordered zeolite nanosheets with open porosity and enhanced diffusion property. In this study, a vapor-phase pillarization (VPP) strategy is developed to prepare the 2D pillared MWW zeolites; the VPP method only uses 1/10 TEOS in the intercalation step, in comparison with the conventional liquid-phase pillarization process. Besides, the additional separation step from liquid solution is not required in the VPP process, and no liquid waste is produced in the VPP operation. The resultant 2D pillared MWW zeolite shows enhanced catalytic activity in the alkylation between benzene and 1-dodecene, in which the conversion of 1-dodecene is more than 40% within 37 h under the harsh reaction conditions (benzene/1-dodecene = 10, WHSV = 20 h-1), and it also exhibits comparable selectivity of 2-LAB (similar to 68%), in comparison with that of traditional 2D pillared MWW zeolites. Furthermore, the 2D pillared MWW zeolites synthesized via the VPP strategy possess an ordered multilamellar structure and exhibit good regeneration performance in the alkylation between benzene and 1-dodecene.