Controllable direct-syntheses of delaminated MWW-type zeolites

• A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein. Two organic amines were introduced into the hydrothermal synthetic system: hexamethyleneimine (HMI), which acted as the structure-directing agent for the MWW layered structure; and dicyclohexylamine (DCHA), in the role of an in-situ delaminating agent. By varying the amount of DCHA, partially and fully delaminated MWW zeolites having two MWW structure layers and one single layer, respectively, were obtained. These were denoted as SCM-1 (Sinopec Composite Material) and SCM-6, respectively. The delaminated materials possess ultra-large external surface areas, and the transmission electron microscopy images illustrated their layered nature. In the reaction of liquid phase benzene alkylation with ethylene, SCM-1, the double-layered MWW zeolite, exhibited far superior catalytic performance compared to zeolite MCM-22.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

Nyckelord

Zeolite

MWW

Alkylation

Ethylbenzene

Delamination

Catalysis

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