Synthesis and catalytic performances of hierarchical SAPO-34 monolith

A novel hierarchical SAPO-34 monolith was prepared by the dry gel conversion of the amorphous silicoaluminophosphate monolith. The obtained material possesses macropores and mesopores besides micropores. The macroporous framework of the hierarchical SAPO-34 is constructed by interconnected spherical aggregates of cubic SAPO-34 crystals and mesopores is formed by the close stacking of cubic SAPO-34 crystals. Catalytic tests show that the hierarchical SAPO-34 possesses high catalytic activity compared with the conventional microporous SAPO-34 for methanol conversion to light olefins (MTO) reaction. The better activity is mainly assigned to the existence of cubic SAPO-34 crystals and the hierarchical porosity.