Department of Inorganic Chemistry, Crystallography, and Mineralogy, Faculty of Sciences, University of Málaga, Campus de Teatinos, 29071, Málaga, Spain.
GPSA - Grupo de Pesquisa Em Separações Por Adsorção, Departamento de Engenharia Química, Universidade Federal Do Ceará, Campus Do Pici, Fortaleza, 60455-760, Brazil.
Environ Sci Pollut Res Int. 2024 May;31(25):37298-37315. doi: 10.1007/s11356-024-33685-0. Epub 2024 May 21.
Five phyllosilicates (kaolinite, montmorillonite, saponite, sepiolite and palygorskite) have been selected as starting materials for the synthesis of zeolites. Among them, kaolinite and montmorillonite display the lowest Si/Al molar ratio leading to aluminosilicates with high crystallinity. Thus, the hydrothermal treatment under basic conditions forms 4A zeolite when kaolinite is used as starting material while 13X zeolite is obtained when montmorillonite is used as starting material. The microporosity and CO-adsorption capacity of the prepared zeolites are directly related to its crystallinity. Thus, in order to improve it, raw phyllosilicates were subjected to a microwave-assisted treatment to remove undesired Mg or Fe-species, which have a negative effect in the assembling of the zeolites by hydrothermal basic conditions in a second step. The highest adsorption value was 3.85 mmol/g at 25 °C and 760 mm of Hg for Mont-A-B sample after the consecutive treatments.
已选择五种层状硅酸盐（高岭石、蒙脱石、皂石、海泡石和坡缕石）作为沸石合成的起始材料。其中，高岭石和蒙脱石的 Si/Al 摩尔比最低，生成的铝硅酸盐结晶度高。因此，在碱性条件下水热处理时，使用高岭石作为起始材料会形成 4A 沸石，而使用蒙脱石作为起始材料则会形成 13X 沸石。所制备沸石的微孔性和 CO 吸附能力与其结晶度直接相关。因此，为了提高其结晶度，对原始层状硅酸盐进行了微波辅助处理，以去除第二步水热碱性条件下组装沸石时具有负面影响的不需要的 Mg 或 Fe 物种。经过连续处理后，Mont-A-B 样品在 25°C 和 760 mmHg 下的最高吸附值为 3.85mmol/g。
