Effect of O2/N2 glow discharge plasma on zeolite extrudates as water adsorbent

Abstract

The suitable desiccant for olefinic compounds is a hydrophilic zeolite adsorbent with low catalytic activity. In the present study, the surface modification of attapulgite-bounded zeolite A by the N2/O2 glow discharge plasma was investigated. The N2 and O2 plasma treatment was applied individually on prepared extrudates before and after calcination. Plasma treatment increased the specific surface area and pore volume of the extrudates, but did not affect the crystallinity of the samples. It was found that the O2 plasma treatment increased the surface acidity. In contrast, the N2 plasma treatment decreased the acidity. The catalytic performances of untreated and N2 plasma-treated extrudates were evaluated in terms of coke formation by using a reactive alkene (1-butene). The coke formation was reduced by 39% in the N2 plasma-treated samples compared to the untreated sample. Moreover, the water sorption capacity of plasma-treated extrudates was higher (∼ 20%) than the untreated ones due to their higher surface area and pore volume.