Excellent Methanol to Olefin Performance of SAPO-34 Crystal Deriving from the Mixed Micropore, Mesopore, and Macropore Architecture

Abstract

Hierarchical aluminosilicophosphate SAPO-34 crystals with designed micropore, mesopore, and macropore architecture are successfully prepared via a simple in situ base etching; the volume ratio of macropore, mesopore, and micropore could be appropriately regulated. With the incorporation of macropore structures into the SAPO-34 zeolites, some thin walls are formed simultaneously; these larger pores and thin walls could certainly shorten the diffusion path length and improve diffusion property, therefore increasing the lifetime as well as ethylene plus propylene selectivity of SAPO-34 catalysts in methanol to olefin reaction. The sample, with a volume ratio of micropore, mesopore, and macropore of about 18:1:87, presents a longer lifetime of 206 min, as well as higher ethylene plus propylene selectivity of 84.35%, in comparison to the conventional microporous sample of 106 min and 77.53%.