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

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 N2 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.

Automated summary

A low hydrothermal temperature, short crystallization time and green strategy were developed to synthesize low-silica SAPO-34. Only under a pressure of 2.7 MPa, pure SAPO-34 with smaller crystal size and moderate acidity was obtained, showing enhanced lifetime and light olefins selectivity in methanol to olefins. A possible formation mechanism of low-silica SAPO-34 was proposed.