Abstract <p>This work presents the results of the synthesis of Fe-ZSM-5 zeolites containing 0.5, 2, and 5 wt % Fe. Modern physicochemical characterization methods, including X-ray diffraction analysis, infrared spectroscopy, scanning electron microscopy, and BET adsorption measurements, were employed to characterize the materials. These methods made it possible to investigate in detail the crystal structure, morphology, and textural properties of the samples and to confirm the successful incorporation of iron into the zeolite framework. XRD demonstrated the preservation of the ZSM-5 structure upon iron incorporation. IR spectroscopy confirmed the presence of Fe-related active sites, whereas SEM and BET adsorption measurements revealed changes in the morphology and specific surface area of the samples. Particular attention was devoted to the investigation of the catalytic properties of the zeolites in the oxidation of phenol in an aqueous medium simulating the treatment of phenol-contaminated wastewater. The reaction was carried out under static conditions at atmospheric pressure and 343 K using an excess of hydrogen peroxide exceeding the stoichiometric amount required for complete oxidation of phenol to CO₂ and H₂O. The results showed that the zeolite containing 2 wt % Fe exhibited the highest catalytic activity, providing the maximum degree of phenol oxidation. This behavior is attributed to an optimal balance between iron-containing active sites and structural characteristics of the material, such as porosity and accessibility of active sites. The samples containing 0.5 and 5 wt % Fe exhibited lower efficiency because of an insufficient number of active sites and their aggregation, respectively. The results obtained demonstrate the promise of Fe-ZSM-5 zeolites for the development of efficient catalytic systems for environmentally safe treatment of phenol-contaminated wastewater, which is important for addressing environmental challenges and promoting sustainable development.</p>