Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
49452 | Catalysis Communications | 2014 | 5 Pages |
•Effects of complex equilibrium on the shape-selectivity of MgO/MCM-22 catalysts•The complex equilibrium was shifted by the addition of HCl.•Improvement in shape-selectivity of MgO/MCM-22 was achieved by addition of HCl.
The role of complex equilibrium in the shape-selectivity of the MgO/MCM-22 catalysts prepared by complexing impregnation was investigated. The presence of hydrochloric acid during the complexing impregnation process resulted in a significant improvement of selectivity for p-xylene production by toluene methylation with dimethyl carbonate over MgO/MCM-22 catalysts. The dramatic performance was ascribed to the designated shifting of the complex equilibrium of malonic acid and Mg2 +, which may alter the coverage of acidic sites on the external surface of zeolite, adjust the pore size of zeolite, and therefore affect the shape-selective performances of the catalysts.
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