Synthesis of low-silica SAPO-34 at lower hydrothermal temperature by additional pressure and its enhanced catalytic performance for methanol to olefin

Abstract

A low hydrothermal temperature, short crystallization time and green strategy is developed for the synthesis of low-silica SAPO-34. The samples were prepared by adjusting the additional pressure with N 2 using TEA as the sole template. The pure SAPO-34 (SP-C4) was obtained only under pressure of 2.7 MPa which possessed the smaller crystal size and moderate acidity and showed enhanced the lifetime and light olefins selectivity in methanol to olefins. And the possible formation mechanism of low-silica SAPO-34 was proposed. • A green strategy is developed for the synthesis of SAPO-34 by additional pressure. • Synthesis of low-silica SAPO-34 at low hydrothermal temperature for short time. • The obtained SAPO-34 possesses the smaller crystal size and moderate acidity. • Enhanced the lifetime (520 min) and light olefins selectivity (85.0%).