A top-down approach to prepare silicoaluminophosphate molecular sieve nanocrystals with improved catalytic activity.

Silicoaluminophosphate SAPO-34 molecular sieve nanocrystals have been prepared by a post-synthesis milling and recrystallization method, which is further proven to be universally applicable to other SAPO molecular sieves. The obtained SAPO-34 with reduced Si enrichment on the external surface shows considerably improved catalytic performance in the MTO reaction.