SAPO-34 MOLECULAR SIEVES AND SYNTHESIS METHOD THEREOF

摘要

The present invention concerns a SAPO-34 molecular sieve and method for preparing the same, whose chemical composition in the anhydrous state is expressed as: mSDA·(Si x Al y P z )O 2 , wherein m is from 0.08 to 0.3, and x is from 0.01 to 0.60, and y is from 0.2 to 0.60, and z is from 0.2 to 0.60, and x + y + z =1. There is the template agent SDA in micropores of the molecular sieve. SDA is organic amine with the structural formula as (CH 3 ) 2 NRN(CH 3 ) 2 , wherein R is saturated straight-chain or branch-chain alkylene group with the number of carbon atoms at a range from 2 to 5. There is a slight Si enrichment phenomenon on the crystal surface of the molecular sieve crystal, and the ratio of the surface Si content to the bulk Si content of the crystal ranges from 1.50 to 1.01. Said SAPO-34 molecular sieve after calcined at a temperature range from 400 to 700 °C in air can be used as a gas adsorbent and catalysts for acid-catalyzed reaction or oxygenate to olefin reaction.