Design and evaluation of Fe-Ni nanostructured catalysts via magnetron sputtering for CO₂-free hydrogen production

Methane pyrolysis offers a promising route for CO₂-free hydrogen production. This study introduces a novel Fe-Ni catalyst architecture, synthesized via magnetron sputtering on γ-Al₂O₃ supports, designed to enhance methane decomposition efficiency. The process enabled the formation of Fe films (200–750 nm thick) with uniformly dispersed Ni nanoclusters (∼2–3 at. %) on the surface. SEM, XRD, and XPS analyses confirmed the controlled nanostructure. Catalytic activity was evaluated at 800 °C using thermogravimetric analysis and a custom-built reactor. Results showed that Fe-Ni catalysts significantly increased hydrogen yield and carbon deposition. Gas analysis revealed elevated H₂ concentrations and minimal CO₂ presence (∼0.1–0.2%), highlighting efficient catalytic performance and low carbon emissions. SEM revealed the growth of carbon nanotube-like structures, suggesting a vapor–liquid–solid growth mechanism. These findings contribute to the development of scalable and eco-friendly catalyst systems for decarbonizing hydrogen production.