Recent advances of the nano-hierarchical SAPO-34 in the methanol-to-olefin (MTO) reaction and other applications

The recent advances in synthesis and catalytic applications of nano-hierarchical SAPO-34 for methanol-to-olefin (MTO) conversion and other reactions have been elaborated in this minireview. The structure, unique properties (e.g., shape selectivity), and diffusion of zeolites and molecular sieves are briefly covered in the first part. An overview of the development of synthetic methods for the preparation of nanosized SAPO-34 and hierarchical SAPO-34 is included in the second and third parts, with focus on the novel and green preparation strategies. The advantages and disadvantages of the different synthetic approaches are discussed in detail, and the relationship between the catalytic performance and the diffusion and acidity is also elucidated. Finally, the updated characterization techniques considering the interconnectivity between the pore channels are outlined.