Modification and sequential treatment of EU-1 zeolite in mild alkali and alkaline-acid conditions

The EU-1 zeolite was treated in mild condition with lower concentration of sodium carbonate and hydrochloric acid. Low-concentration sodium carbonate alkaline solution can remove amorphous Si/Al species in the gap among EU-1 crystallines on a targeted site. In addition, it can enlarge mesopore volume and specific surface area without causing great damage of EU-1 framework. A little of non-framework Al species is deposited certainly after alkaline treatment. After that, the diluted hydrochloric acid is applied to remove non-framework acid center to reduce side reaction in xylene isomerization. The mesoporous molecular sieve was obtained by the alkali-acid treatment.76