β Zeolite Nanostructures with a High SiO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub> Ratio for the Adsorption of Volatile Organic Compounds
Jie Wang, Shiwei Cao, Yu Sun, Xiaoling Meng, Jianhui Wei, Yafen Ge, Бо Лю, Yanjun Gong, Zhihong Li, Guang Mo
Abstract
β Zeolites with a high SiO2/Al2O3 ratio (SAR) are of great importance in the adsorption of VOCs. However, the higher the SAR of β zeolites, the more difficult they are to synthesize because of kinetic limitations. Herein, adopting a seed-assisted synthesis ensures that β zeolites have a high yield and a wide range of SAR (up to 600, named Nano-B600). Furthermore, a comprehensive insight into the evolution of particle structure in the synthesis system and the influence of seed crystals was gained by a synchrotron radiation small-angle X-ray scattering (SAXS) technology, FT-IR, SEM, and TEM. The results showed that the species dissolved from seed crystals present appropriate fractal structure, promoting the formation of a large number of structural units and leading to the rapid growth of β zeolites. Typically, Nano-B600 possesses a larger surface area and mesopore volume as well as strong hydrophobicity, which shows super toluene adsorption capacity, with an increase of 43% compared to that of the bulk β zeolites with a similar SAR, and can also maintain adsorption performance under moisture. For other organic compounds, Nano-B600 shows a much higher adsorption capacity compared to that of the usual ZSM-5 and Y zeolites. The high-silica nanosized β zeolites demonstrate strong applicability as super adsorption materials for VOCs.