Crystal Growth and Morphology Control of SCM-10 Zeolites

TL;DR

This paper explores how to control the shape and growth of SCM-10 zeolite crystals by adjusting synthesis conditions and heteroatom substitution.

Contribution

The study establishes specific rules for morphology control of SCM-10 zeolites through synthesis parameters and heteroatom substitution.

Findings

SCM-10 crystallizes via an induction period followed by rapid growth, forming needle-like crystals.

Changing SiO2/B2O3 ratio alters morphology from needles to plates, while higher crystallization temperatures produce nanowires.

Heteroatom substitution (Al, V, Fe, Ge) leads to distinct morphology changes, including nanoparticles and nanowires.

Abstract

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.

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