The role of layered double hydroxides shell in enhancing the adsorption capacity of NaY zeolite for toluene in wet conditions

Abstract

Surface modification of zeolite is known to enhance its adsorption capacity for volatile organic compounds (VOCs). In this study, a hydrophobic adsorbent, NaY@LDHs, with layered double hydroxides (LDHs) as the shell and NaY zeolite as the core, was successfully synthesized. It was found that treating LDHs with ethanol can result in a larger specific surface area and pore volume, enhancing the adsorption performance of toluene under wet conditions. SEM imaging reveals that the LDHs shell grows vertically on the surface of the NaY zeolite. The dynamic adsorption experiment of toluene showed that under humid conditions, NaY@LDHs exhibited a saturated adsorption capacity of 32.42 mg/g, representing a significant 87% increase compared to the parent NaY zeolite. The kinetic results show that the adsorption of toluene on NaY@LDHs is primarily physical adsorption, and other factors influence the adsorption process in addition to intraparticle diffusion. Therefore, the air layer formed by the LDHs shell on the surface of NaY zeolite imparts a hydrophobic effect, making NaY@LDHs a promising material for adsorbing volatile organic compounds in a wet environment.