Adsorption and Desorption Characteristics of Nano-Metal-Modified Zeolite for Removal of Oxygenated Volatile Organic Compounds

Oxygenated volatile organic compounds are key precursors of secondary photochemical pollutants. To enhance their removal, NaY–zeolite was modified with nano-sized metals (Fe, Ti, Si, or Ce) using impregnation and sol–gel methods. Dynamic adsorption experiments were conducted to evaluate the adsorption of ethanol, acetaldehyde, and ethyl acetate under various condition modifications, including of the impregnation concentration, treatment time, and calcination temperature. The structural and surface properties of the modified zeolites were characterized by N₂ adsorption–desorption isotherm, X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR) analyses. The results indicated that the metal-loaded zeolites exhibited significantly higher adsorption capacities than the unmodified NaY–zeolite. Among them, silicon-modified zeolite showed the best performance, with its adsorption capacities for ethanol, acetaldehyde, and ethyl acetate increasing from 32.4, 72.4, and 123.0 mg·g⁻¹ to 49.82, 88.94, and 207.02 mg·g⁻¹, corresponding to improvements of 37%, 23%, and 70%. The optimal modification conditions involved the use of silicon as the modifier with a 7% impregnation concentration, a 12 h impregnation time, and calcination at 350 °C; the zeolite modified under these conditions was characterized by a good adsorption capacity and low preparation cost. This study suggests newly designed adsorber materials suitable for highly efficient treatment of oxygenated volatile organic compounds.