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An environmentally-benign way of producing hydrogen is methane decomposition. This study focused on methane decomposition using Fe and Fe-Ni catalysts, which were dispersed over different supports by the wet-impregnation method. We observed the effect of modifying ZrO₂ with La₂O₃ and WO₃ in terms of H₂ yield and carbon deposits. The modification led to a higher H₂ yield in all cases and WO₃-modified support gave the highest yield of about 90% and was stable throughout the reaction period. The reaction conditions were at 1 atm, 800 °C, and 4000 mL(hg_cat)⁻¹ space velocity. Adding Ni to Fe/x-ZrO₂ gave a higher H₂ yield and stability for ZrO₂ and La₂O₃ + ZrO₂-supported catalysts whose prior performances and stabilities were very poor. Catalyst samples were analyzed by characterization techniques like X-ray diffraction (XRD), nitrogen physisorption, temperature-programmed reduction (TPR), thermo-gravimetric analysis (TGA), and Raman spectroscopy. The phases of iron and the supports were identified using XRD while the BET revealed a significant decrease in the specific surface areas of fresh catalysts relative to supports. A progressive change in Fe’s oxidation state from Fe³⁺ to Fe⁰ was observed from the H₂-TPR results. The carbon deposits on Fe/ZrO₂ and Fe/La₂O₃ + ZrO₂ are mainly amorphous, while Fe/WO₃ + ZrO₂ and Fe-Ni/x-ZrO₂ are characterized by graphitic carbon.