Crystal Growth and Morphology Control of SCM-10 Zeolites

SCM-10 is an SFE-type borosilicate zeolite featuring one-dimensional 12-ring channels and holds promise for catalytic and separation applications, yet its crystallization and morphology control remain insufficiently understood. Herein, we investigate the crystallization of SCM-10 and elucidate the effects of synthesis parameters, including SiO₂/B₂O₃, OSDA/SiO₂, and H₂O/SiO₂ molar ratios, crystallization temperature, and heteroatom substitution, on crystal morphology. SCM-10 crystallizes via an induction period (30 h) followed by rapid crystal growth (12 h), yielding uniform needle-like crystals with dimensions of 0.05 × 1 μm (diameter × length; aspect ratio = 20). Increasing the SiO₂/B₂O₃ ratio induces a morphology transition from needles to plates, whereas variations in the OSDA/SiO₂ and H₂O/SiO₂ ratios largely preserve the needle-like morphology. Elevating the crystallization temperature transforms needles into nanowires, with the aspect ratio rising to 83 (0.03 × 2.5 μm). Heteroatom substitution further induces distinct morphology modulation: Al yields nanoparticles (100 nm), V shortens crystal lengths to 500 nm (50 × 500 nm; aspect ratio = 10), Fe produces nanowires (0.02 × 1.3 μm; aspect ratio = 65), and Ge forms peanut-like needle aggregates (0.05 × 10 μm; aspect ratio = 200). This work establishes morphology-regulation rules for SCM-10, enabling the rational design of tailored morphologies for applications.