Grinding synthesis of SAPO-44 in the presence of dual templates: a promising catalyst for methanol to propylene reaction

The grinding synthesis of CHA-type SAPO-44 molecular sieves were firstly achieved in the presence of dual templates. The structure and physicochemical properties of several selected SAPO-44 samples were analyzed by XRD, FT-IR, SEM, N₂ adsorption–desorption, EDS, and NH₃-TPD techniques. It was found that the composition of dual templates has a greater influence on the Si content, crystal size, specific surface area and pore volume, acid strength and distribution of SAPO-44. In comparison to the SAPO-44 catalyst guided by the single template, the dual templates directed SAPO-44 catalysts showed more excellent catalytic performance in the methanol-to-olefin (MTO) reaction, with their catalytic lifetime extending from 90 to 320 min and P/E ratio reaching up to 50. The outstanding catalytic performance exhibited by these SAPO-44 catalysts demonstrated their high application prospect in the methanol to propylene process.