Synthesis, characterization, and catalytic properties of MWW zeolite with variable Si/Al ratios

Synthesis of aluminosilicate MWW zeolite with variable Si/Al ratios from deboronated ERB-1 zeolite through a process of structural conversion has been studied and the obtained material has been characterized in detail. Incorporation of aluminum species into the framework of deboronated ERB-1 zeolite and the acidity of calcined MWW zeolite have been confirmed by a number of physicochemical techniques. Aluminum species in the lamellar MWW zeolite precursor are not thermally stable, and partial dealumination takes place during the calcination process. MWW zeolite shows strong Brönsted acidity, and the amount of Brönsted acid sites is closely related with the amount of framework aluminum in MWW zeolite. Disproportionation of toluene was carried out over MWW zeolite with different Si/Al ratios, and the catalytic performance has been correlated with the Brönsted acidity of MWW zeolite.