Mechanisms of Quick Zeolite Beta Crystallization

作者：Hould Nathan^*; Haouas Mohamed; Nikolakis Vladimiros; Taulelle Francis; Lobo Raul

来源：Chemistry of Materials, 2012, 24(18): 3621-3632.

DOI：10.1021/cm3020995

• zeolite beta
• small angle x-ray scattering
• small angle neutron scattering
• nucleation
• nuclear magnetic resonance
• colloid

Silicate self-assembly and zeolite beta crystallization in the presence of 4,4%26apos;-trimethylenebis(N-methyl, N-benzyl piperidinium) (TMP2+) structure directing agent were studied using a combination of Si-29 and Al-27 nuclear magnetic resonance (NMR), small angle scattering (SAS), and attenuated total reflectance Fourier transform infrared (ATR/FTIR) spectroscopy. Crystallization of nanosized siliceous TMP2+ zeolite beta proceeds along three populations of particles (i.e., primary, secondary, and tertiary), differing in size and internal structure similar to crystallization of aluminum containing zeolite beta with tetraethylammonium (TEA(+)) as structure directing agent. Aluminosilicate TMP2+ zeolite beta, however, crystallizes along a very unique pathway, wherein secondary particles are final partially crystalline colloidally stable zeolite beta. TMP2+ zeolite beta crystallizes quickly when compared to TEA(+) zeolite beta, which takes nearly a hundred hours to crystallize under similar synthesis conditions.

• 出版日期2012-9-25