Clean hydrogen production offers a viable alternative in the transition to a greener and more sustainable energy future. This study introduces a novel method for enhancing Fe/Al2O3 catalysts using La2O3 and CeO2 doping, aimed at improving hydrogen production via methane decomposition. It addresses the critical challenge of modulating metal-support interaction. Employing ultrasonication in the catalyst preparation, we observed through XRD, H2-TPR, H2 chemisorption, Raman spectroscopy, TGA, and TPO analyses that La2O3 addition prevents FeAl2O4 formation and increases Fe reduction and active sites. Catalysts assisted by ultrasound outperform traditional methods, exhibiting a consistent and significant increase in conversion and yield efficiencies. The La2O3-modified catalysts outperformed the standard Fe/Al2O3 catalyst in methane decomposition. At 800 °C, they demonstrated enhanced activity and stability under demanding conditions, achieving a methane conversion of 93% and hydrogen yield of 84%. This approach boosts hydrogen production and contributes to the development of sustainable and efficient energy solutions.