Synthesis of transition metal-doped ETS-10 zeolite: Effect of the metal addition on the crystallization and morphology and their catalytic application for organic transformation

The crystallinity and morphology of the zeolites have a significant effect on their catalytic performance. Herein, the influence of the introduced metal and copolymer in the synthesis gel on the crystallinity and morphology of the synthesized M-ETS-10 (M=Fe, Co, Ni, Cu) zeolites and on their catalytic activity were investigated. The crystallinity (110%) of the M-ETS-10 (M=Fe, Co, Ni, Cu) was enhanced; the morphology of Fe(or Co)-ETS-10 was changed to imperfect tetragonal bipyramidal shapes, and Ni(or Cu)-ETS-10 turned into irregular large particles consisted of defective tetragonal bipyramidal. Incorporating copolymer into the gel contributed to all the hierarchical M-ETS-10-H being present multi-layered structure consisted of nanosheets. The hierarchical Cu-ETS-10-H exhibited superior catalytic activity than M-ETS-10-H and Cu-ETS-10 in the C–C bond cleavage and decarboxylative hydrosulfonylation reactions. This was attributed to the presence of Lewis basic sites, reversible transformation of Cu²⁺ to Cu⁺, as well as the hierarchical pore structure.