Hierarchical zeolite Y prepared by sequential acid washing and alkaline treatment in the presence of surfactant micelles, has been emerging as one of the most promising approach to introduce controlled mesoporosity into zeolite Y crystals. However, the synthesis of mesostructured Y by a simple procedure still remains a challenge. Herein, the goal was achieved by designing of a low-cost surfactant [(CH3O)3SiC3H6N(CH3)2C16H37]Cl (denoted as “TPHAC”). In this strategy, dealumination arose from coordination of -Si-(OH)3 (product of hydrolysis of THPAC) with framework aluminum ions and controlled mesoporosity was introduced into zeolite crystals through a surfactant approach, which exhibits a potential way to synthesize mesoporous Y zeolite from NaY with low Si/Al.

•Mesoporous aluminosilicates with reduced particle size were synthesized.•The addition of Tween-20 increases the hydration degree of complex micelles.•The procedures are as simple as the direct synthesis method.We report a facile strategy for synthesis of hydrothermally stable mesoporous aluminosilicates (MAs) from zeolite Y precursors by adding small amount of Tween-20. By the addition of suitable amount of Tween-20, P123-Tween complex micelles formed due to the interaction between hydrophobic chain of Tween and PPO units of P123. The hydrophilicity of the complex micelles was enhanced due to the incorporation of PEO units of Tween. As a result of this, the micelles could be well dispersed and MAs with reduced particle size could be readily obtained.

•Template P123 was effectively removed by ultrasonic extraction from MA.•MA treated by ultrasonic extraction shows excellent structural performance.•The recovered P123 have been reused as the template in the synthesis procedure of MA.High synthesis cost of mesoporous aluminosilicates (MA) limits their practical application. Recycling of copolymer template employed in preparation of MA is an effective way to reduce the synthesis cost. An ultrasonic extraction strategy for recycling of organic template P123 in MAs is reported. Effects of different extraction parameters on P123 recovery are investigated and the optimum conditions are obtained. 75.0% P123 is recovered from MAs within 10 min by one-step ultrasonication. Characterizations indicated that the resulting P123-free MA (MA-U) exhibits excellent properties compared with that of calcined products. Moreover, recovered P123 can be employed to synthesize high hydrothermally stable MA. This investigation provides a facile strategy to recycle P123 from MA.

Hydrothermally stable hierarchical materials with macro-meso-micropores were synthesized by combination of precursor assembly and PS/P123 dual templates. Precursor assembly aims at the formation of meso-micropores and improving the hydrothermal stability, and PS microspheres aim at the introduction of macropores. Moreover, worm-like mesopores vertical to the surface of PS microspheres were present, which achieve the full interconnection of macro-meso-micropores. The resulting aluminosilicates with hierarchical pores and high hydrothermal stability showed excellent catalytic cracking properties for heavy oil.

•Mesoporous aluminosilicate with acidity and hydrothermal stability was developed.•Hydrothermal stability was improved by Beta zeolite precursors in zeolite walls.•Al was introduced into the mesophases, and thus the acidity was improved.•Bimodal zeolites demonstrated superior catalytic properties for heavy oil FCC.A general synthetic route of bimodal micro-mesoporous aluminosilicates with strong acidity and excellent hydrothermal stability has been developed. This method is built on the understanding that mesoporous aluminosilicates with high hydrothermal stability can be obtained via assembly of zeolite precursors in acidic conditions by copolymer templates, and the acidity can be improved by the introduction of Al species in neutral and alkaline systems. It is proposed that in order to obtain the mesoporous aluminosilicates with simultaneously strong acidity and excellent hydrothermal stability, an important requirement is that the paradox between stability and acidity must be harmonized. In this article, the crystallization of the resulting aluminosilicates was significantly improved by taking advantage of the Beta zeolite precursors in acidic media. When the mesostructure was basically formed, the pH of the reaction system was adjusted from strong acid to neutral, followed by a second hydrothermal crystallization, during which a large amount of Al could be introduced into the mesophases. XRF and Al NMR show that BPs possessed a high tetrahedrally coordinated Al loading. Py-IR results reveal that the total amount of Brønsted and Lewis acid sites increases 7.23 times. Such bimodal micro-mesoporous aluminosilicates demonstrated superior catalytic properties for heavy crude oil catalytic cracking, because of the increased hydrothermal stability and acidity. Our achievements have added new contributions to understanding the preparation of mesoporous aluminosilicates with strong acidity and excellent hydrothermal stability, which sheds a light on the practical application of mesoporous zeolites in petrochemical industry.

Through a combination of Y zeolite precursors and the pH-adjusting method, bimodal aluminosilicates (denoted as LFs) with strong acidity and excellent hydrothermal stability were synthesized. The hydrothermal stability of the resulting aluminosilicates was improved greatly by taking advantage of Y zeolite precursors (the retaining ratio of the total surface area was 33% after hydrothermal treatment in 100% water vapor at 800 °C for 15 h). When the mesostructure was basically formed in the first crystallization, the pH of the reaction system was adjusted from strong acid to neutral, followed by the second hydrothermal crystallization, during which a large amount of Al could be introduced into the mesophases. XRF and Al NMR showed that LFs possessed a high alumina loading (with SiO2/Al2O3 molar ratio of 24.4) and most of the Al was tetrahydrally coordinated. NH3-TPD results indicated that the total amount of acid sites increased 12.9 times compared with that of ZF (without pH adjustment). The resulting aluminosilicates with simultaneously enhanced acidity and hydrothermal stability showed superior catalytic properties when used in heavy crude oil catalytic cracking. Our achievements have developed a general synthetic route of bimodal aluminosilicates with strong acidity and excellent hydrothermal stability.