Size-controlled synthesis of MCM-49 zeolite from NaX for liquid-phase alkylation of benzene with ethylene

作者：Xing Enhui; Shi Yanchun; Xie Wenhua; Zhang Fengmei^*; Mu Xuhong; Shu Xingtian

来源：Microporous and Mesoporous Materials, 2016, 236: 54-62.

DOI：10.1016/j.micromeso.2016.08.026

• Size-controlled synthesis
• NaX
• MCM-49
• Liquid-phase alkylation
• Ethylbenzene

Size-controlled synthesis of MCM-49 zeolite (MWW, SiO2/Al2O3 > 20) was achieved in presence of parent zeolite NaX (FAU, SiO2/Al2O3 = 2.5), hexamethyleneimine (HMI), NaOH and SiO2, with d6r as a common composite building unit between FAU (d6r and sod) and MWW (d6r and mel) structure. The samples prepared at different crystallization stages were characterized by XRD, SEM, Si-29/Al-27/C-13 MAS NMR to investigate the intermediates during the direct zeolite-zeolite transformation from NaX to MCM-49. H-MCM-49 transformed from NaX has smaller and more regular MWW crystal sizes than conventional H-MCM-49. Also an increase in the acid sites determined by pyridine-FTIR was observed. A substantial improvement in both ethylene conversion and ethylbenzene selectivity was achieved over H-MCM-49 transformed from NaX because of smaller crystal sizes and more acid sites.

• 出版日期2016-12-1
• 单位中国石油化工股份有限公司石油化工科学研究院