Synthesis of Cs-ABW nanozeolite in organotemplate-free system

• Main Authors: Ali Ghrear, Tamara Mahmoud, Rigolet, Severinne, Daou, T. Jean, Mintova, Svetlana, Ling, Tau Chuan, Tan, Soon Huat, Ng, Eng Poh
• Format: Article
• Published: Elsevier 2019
• Subjects: Q Science (General); QD Chemistry; QH Natural history; TP Chemical technology
• Online Access: http://eprints.um.edu.my/20127/; https://doi.org/10.1016/j.micromeso.2018.10.014
• Institution: Universiti Malaya

Cesium-aluminosilicate zeolite nanocrystals with ABW framework structure are synthesized free of organic template using hydrothermal approach. The crystallization process of Cs-ABW zeolite nanocrystals by varying the initial gel molar composition, heating temperature and crystallization time was studied. More detailed investigations of the formation of Cs-ABW nanozeolite using a reactive clear precursor hydrogel (4SiO2:1Al2O3:16Cs2O:160H2O) were then carried out. Fully crystalline Cs-ABW nanozeolites were obtained within 120 min at 180 °C and 22 bar, which is considerably faster and safer in comparison to the currently available method involving treatment at 695 °C, 1000 bar and 46 h. The Cs-ABW nanocrystals have grain shape morphology with a mean size of 32 nm and they do not agglomerate for long durations. The nanosized Cs-ABW zeolite has high alumina content (Si/Al ratio = 1.04). These nanocrystals can be prepared in high solid yield (ca. 82%) thus offering a promising route for large-scale production of highly basic zeolite nanoparticles.