Synthesis of hierarchical SAPO-34 nanocrystals with improved catalytic performance for methanol to olefins

SAPO-34 molecular sieve was hydrothermally synthesized by using organosilane phenylaminopropyl-tri methoxysilane (PHAPTMS) as a part of silicon source and tetraethylammonium hydroxide as microporous template at 160 degrees C. The XRD, SEM and N2 adsorption/desorption characterizations revealed the hierarchical SAPO-34 is a nanocrystal assembly of 50 nm particles prepared in the system. The catalyst showed improved stability and unusual selectivity of propylene and butylene in methanol to olefins reaction by introducing the mesoporous structure and changing the surface acid sites distribution. The yield of light olefins in hydrocarbons was up to 86%, the selectivity of C3= and C4= reached more than 40% and 10%. (C) 2016 Elsevier B.V. All rights reserved.