Effects of Post-Synthesis Activation and Relative Humidity on Adsorption Performance of ZIF-8 for Capturing Toluene from a Gas Phase in a Continuous Mode

Zeolitic imidazolate framework-8 (ZIF-8) was used as an adsorbent for the removal of toluene in its gas phase at different relative humidity (RH). High-purity ZIF-8 with an average particle size of 0.64 mu m synthesized from an aqueous solution at room temperature, and then characterized by X-ray diffraction (XRD), fourier transform infrared (FT-IR) and scanning electron microscopy (SEM) techniques. Dynamic adsorption (continuous mode) experiments of toluene on ZIF-8 were studied using breakthrough curves. The effects of thermal pretreatment (activation) under dry air and N-2 atmospheres on the adsorbent performances was studied. ZIF-8 activated at 300 degrees C for 3 h under dry air showed the highest adsorption capacity of 562.17 mg.g(-1). Furthermore, it was observed that the adsorption of toluene on ZIF-8 was significantly decreased at 80% RH. The experimental data of dynamic adsorption well fitted into the Thomas and Yan mathematical models.