Additive-free synthesis of house-of-card NaX zeolite for supporting amine: An efficient adsorbent for SO2 removal

• Published in: Separation and purification technology 2025-02, Vol.354, p.129481, Article 129481
• Main Authors: Zhang, Qiongdan, Ye, Ming, Lei, Yuanyi, Wang, Heng, Zheng, Yong, Xiao, Yihong, Liu, Fujian, Jiang, Lilong
• Format: Article
• Language: English
• Subjects: Hierarchical; House-of-card-like morphology; Ionic liquid; NaX zeolite; Sulfur dioxide adsorption
• ISSN: 1383-5866
• DOI: 10.1016/j.seppur.2024.129481

[Display omitted] The efficient adsorption of sulfur dioxide (SO2) is crucial for purifying exhaust gases, and zeolites are promising adsorbents due to their low cost and excellent stability. However, developing FAU-type zeolites with high adsorption capacities and selectivities remains challenging due to their narrow pores and limited adsorption sites. Herein, an additive-free synthesis strategy is proposed to facilely obtain NaX zeolites (X-HCL) with the house-of-card-like morphology. The hierarchical structure of X-HCL not only benefits the removal of SO2 through favorable spatial diffusion, but also promotes the loading of basic adsorption sites- [caprolactam] [tetrabutylammonium bromide] (CT) ionic liquid. The obtained CT/X-HCL adsorbent demonstrates remarkable SO2 adsorption capacity (10.58 mmol/g) and cyclic stability, as well as great selectivity of SO2/N2 (1673) and SO2/CO2 (219) due to the strong affinity of CT towards SO2. Moreover, co-feeding with water vapor benefits the adsorption of SO2 on CT/X-HCL owing to the enhanced chemisorption of hydrated CT for SO2. This research provides new insights into the construction of hierarchical zeolite for efficient adsorption and separation of SO2.