摘要 |
Ferrierite is prepared by maintaining at a temperature from about 170 DEG to 215 DEG C an aqueous mixture of amorphous silica-alumina and sodium and potassium compounds wherein from about 65 to about 90 mol % of the alkali metal as X2O wherein X represents Na and K originates from salts of at least one polybasic acid having a pK value greater than 10 DEG at 18 DEG C for the highest dissociation step, and the molar fraction of potassium to total sodium and potassium content is from about 10 to 45%, until ferrierite crystals are formed. |