Adsorption of toluene on silicalite‐1/NaY composites: Influence of NaY pretreatment on hydrophobic properties

Abstract

The surface hydrophobic modification of NaY zeolite was discussed to improve the adsorption capacity of NaY in VOCs under wet conditions. Silicalite‐1/NaY composites were hydrothermally synthesized in silicalite‐1 precursor solution using NaY (treated with HCl and NaOH) as seed. The textural, porosity, morphology, and adsorption properties of these adsorbents were characterized by X‐ray diffraction, N2 adsorption–desorption, scanning electron microscopy, inductively coupled plasma atomic emission spectroscopy measurements, sequential X‐ray fluorescence spectrometer, and static adsorption experiment of water and dynamic adsorption tests under wet and dry condition. Results showed that the static water adsorption capacity of the composites was greatly reduced compared with pure NaY and the dynamic adsorption of toluene under both wet and dry conditions (relative humidity of 50% and 0%) indicated that the composites possessed high dynamic adsorptive capacity and hydrophobic properties. Among these composites, the sample synthesized by NaY (NaOH pretreatment) displayed the best hydrophobic properties in the competitive adsorption of water and toluene with a toluene adsorption capacity of 56 mg/g.