Experimental and simulation study of volatile organic compounds adsorption over natural Opoka based zeolite 13X

This study synthesized FAU-type zeolite 13X from natural Opoka via hydrothermal method and established its atomic structural model through computational simulations. Its adsorption properties and mechanisms for five typical volatile organic compounds (VOCs) were systematically investigated through material characterization, adsorption experiments, and Monte Carlo simulations. Experimental results demonstrated that the synthesized zeolite 13X exhibits excellent adsorption performance, with a high specific surface area of 620 m 2 /g and a total pore volume of 0.30 cm 3 /g, of which micropores account for 83.3 %. It exhibited particularly strong adsorption capacity for low molecular weight, low boiling point VOCs (acetone, toluene, and n-hexane), with acetone showing superior adsorption on zeolite than commercial activated carbon. Molecular simulations revealed that acetone's strong adsorption on the ideal zeolite 13X model is primarily driven by electrostatic interactions, while the adsorption of toluene and 1,2,4-trimethylbenzene is governed by van der Waals forces. In contrast, n-hexane and n-decane showed poor adsorption due to electrostatic repulsion and weak van der Waals interactions. A comparison of experimental and simulation results indicated that the presence of a small fraction of mesoporous structures in the synthesized zeolite 13X notably enhances its adsorption performance for straight-chain or high molecular weight VOCs. This finding provides a new strategy for optimizing the design of microporous molecular sieves. Furthermore, the zeolite exhibits excellent thermal stability, regeneration capability, and cycling performance, making it a promising candidate for VOC abatement applications. • High-performance VOCs adsorbent zeolite 13X was synthesized from natural Opoka. • Mesopores improve performance for straight-chain/high-molecular weight VOCs. • Superior polar VOCs adsorption properties due to strong electrostatic interactions • Adsorption mechanism was studied using experiments and simulation.