Obtaining of Mesoporous Aluminosilicates with High Hydrothermal Stability by Composite Organic Templates: Utility and Mechanism

Abstract

We have reported the synthesis of mesoporous aluminosilicates (MAs) with high hydrothermal stability via assembly of basic characteristic structure units of typical microporous zeolite Y. In spite of this, high consumption of organic template and H 2 O remains a major obstacle to its industrial application. Herein, a facile and effective strategy called "composite templates" was employed to decrease significantly the amount of P123 and H 2 O. In this method, composite micelles of P123/ poly(vinyl alcohol) (PVA) could be more easily dispersed in the solution due to the lowering of water's surface tension caused by the free hydroxyl groups of PVA. Moreover, the improved assembly ability of composite micelles in high concentration solution leads to the synthesis of hydrothermally stable MAs with 45% decrease of organic template P123 and 81% that of water amount. It was found that by the introduction of composite templates, the textural properties such as the surface area of materials, volume of pore, size of pore, and thickness were enlarged simultaneously. Meanwhile, this article presented an understanding into the assembly of composite micelles in the process of synthesis of MAs.

Synthesis of Well-Ordered Mesoporous Aluminosilicates with High Aluminum Contents: The Challenge and the Promise

“…In addition, our group synthesized hydrothermally stable MAs via the self-assembly of zeolite Y and β precursors . Moreover, the novel strategy could decrease the synthesis cost by utilizing composite templates, such as P123/SDS, P123/SDMBS, P123/PVA, P123/PPG, P123/AES, and P123/Urea . Unfortunately, these innovative procedures are complicated to operate and difficult to be extended to other synthesis systems.…”

Synthesis of Mesoporous Aluminosilicates with Moderate Acidity and High Hydrothermal Stability by Acid-Free Method

“…The reason is that these syntheses mostly involve a dilute template solution, which is requisite for the activity of micelles. On the basis of this, composite templates such as SDS/P123, SDMBS/P123, PVA/P123, PPG/P123, AES/P123, and urea/P123 were adopted to enhance the hydrophilicity of micelles in high-concentration template solutions. As a direct result of this, the consumption of water and organic templates decreased greatly.…”

Preparation of Mesoporous Aluminosilicates with Decreased Dosage of Organic Template and Water: Insights into the HLB Effect of the Cotemplate

“…MAs have been attracting intense research interest due to their large pores and high surface area. − Improving hydrothermal stability is crucial for their practical applications but challenging in the industrial process. To settle this issue, the author’s group obtained hydrothermally stable MAs via the self-assembly of zeolite Y precursors. − However, a means to synthesize MAs with hydrothermal stability with decreased consumption amounts of organic surfactants and water is still a challenging goal.…”

“…This inherently enhanced the hydrophilicity and thus the dispersity of the composite micelles, presenting the well-ordered mesophase. Based on the same principle, sodium dodecyl sulfate with polarized sulfonic acid groups, alcohol ether sulfate (AES) with 3 ether bonds and 1 hydroxyl, and hydrophilic polymer poly­(vinyl alcohol) with multi-hydroxyl were introduced into the high-concentration template F68 . Moreover, decreased consumption of template and water was obtained due to the increase in micelle dispersity with the incorporation of these hydrophilic cotemplates.…”