Optimization of Hierarchical Structures for Beta Zeolites by Post-Synthetic Base Leaching
| Autor: | Sarah Kobaslija, Michele L. Ostraat, Sergio Fernandez, Tatiana S. Pilyugina, Jeremy T. O’Brien, Ke Zhang, John A. Lawrence |
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| Rok vydání: | 2016 |
| Předmět: |
inorganic chemicals
Chemistry General Chemical Engineering Inorganic chemistry food and beverages Single step 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Industrial and Manufacturing Engineering 0104 chemical sciences Leaching (metallurgy) 0210 nano-technology Mesoporous material Zeolite |
| Zdroj: | Industrial & Engineering Chemistry Research. 55:8567-8575 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/acs.iecr.6b00912 |
| Popis: | Hierarchical structures of zeolite beta with Si/Al ratios in the range of 14–250 are optimized by post-synthetic base leaching, including direct alkaline treatments in NaOH solutions, fluorination–desilication sequences, and alkaline treatments in the presence of tetrapropylammonium cations (TPA+) as the pore-directing agent (PDA). Mesoporosity can be conveniently obtained by a single step of base leaching in NaOH (e.g., 0.2 M NaOH at 65 °C) for high Al beta zeolites (Si/Al 20), the alkaline treatments in the presence of PDA (e.g., TPA+) are crucial for creating mesopores without sacrificing the original zeolite framework. In the absence of TPA+, the high Si zeolite framework is very sensitive to NaOH leaching, resulting in severe structural amorphization. High Al zeolite beta can also be leached by alkaline treatments with TPA+, which features sm... |
| Databáze: | OpenAIRE |
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