Investigating the Cold Plasma Surface Modification of Kaolin- and Attapulgite-Bound Zeolite A

• Published in: Journal of industrial and engineering chemistry (Seoul, Korea) 2022, 106(0), , pp.113-127
• Main Authors: Ejtemaei, Mahboobeh, Sadighi, Sepehr, Rashidzadeh, Mehdi, Khorram, Sirous, Back, Jan O., Penner, Simon, Noisternig, Michael F., Salari, Dariush, Niaei, Aligholi
• Format: Article
• Language: English
• Subjects: Adsorbent; Argon glow discharge; Clay; Plasma; Surface modification; Zeolite; 화학공학
• ISSN: 1226-086X; 1876-794X
• DOI: 10.1016/j.jiec.2021.10.020

[Display omitted] •Kaolin- and attapulgite-bound zeolite A were prepared from the synthesized zeolite.•Ar glow discharge plasma treatment was applied on prepared extrudates.•Attapulgite extrudates were influenced more effectively than kaolin extrudates.•The water adsorption capacity decreased after plasma treatment.•The plasma-treated sample was more resistant to coke formation from 1-butene and 1,3-butadiene. Hydrophilic zeolites with low catalytic activity are considered as suitable adsorbents for drying gas streams containing olefinic compounds. In this contribution, the surface treatment of kaolin and attapulgite/zeolite A extrudates is investigated using argon glow discharge plasma. The zeolite is synthesized from kaolin using the hydrothermal method. Surface and bulk characterization is performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), N2 physisorption, Fourier-transform infrared (FT-IR) spectroscopy, temperature-programmed-desorption (TPD) of NH3 and X-ray photoelectron spectroscopy (XPS) techniques. Plasma treatment increases surface area and pore volume, but it decreases the weak acidic site density of the extrudates. The obtained results show that attapulgite/zeolite extrudates are more affected by plasma treatment than kaolin/zeolite extrudates. The catalytic activity of untreated and plasma-treated extrudates are compared with respect to coke formation resulting from 1-butene and 1,3-butadiene. The plasma-treated sample is more resistant to coke formation (∼35% decrease compared to untreated one). The potassium contents of extrudates decreased as a result of sputtering loosely bound potassium cations on the crystal surface by argon ions, which led to a decrease in water sorption capacity (by ∼15% of the initial sorption capacity).