Cube-shaped metal foam catalyst for natural gas pre-reforming in solid oxide fuel cell systems

Cube-shaped metal foam catalysts, coated with Ni and 0.5 wt% Ru, were developed for natural gas pre-reforming in solid oxide fuel cell (SOFC) systems. Pre-reforming occurs at temperatures below 500 °C and requires catalysts with good thermal conductivity and low-temperature activity. In this study, NiCrAl metal foam surfaces were coated with Ni(X mM)/MgAl₂O₄ and Ru/Ni(X mM)/MgAl₂O₄ catalysts via deposition–precipitation at various Ni solution concentrations (X = 100–500 mM). Ni plate particles were uniformly formed on the metal foam, exhibiting a desert rose-like shape with increasing Ni concentration. The Ru/Ni/MgAl₂O₄ foam catalysts containing 0.5 wt% Ru had large metallic surface areas and low-temperature reducibility due to the synergistic effect between Ni and Ru. The Ru/Ni(300 mM)/MgAl₂O₄ coated foam catalyst effectively suppressed metal aggregation and enhanced low-temperature reducibility, thereby exhibiting higher carbon conversion compared to Ni(300 mM)/MgAl₂O₄ and Ru/MgAl₂O₄ catalysts at 500 °C, 8000 h⁻¹ and a steam-to-carbon (S/C) ratio of 3. Additionally, the Ru/Ni(300 mM) catalyst demonstrated better coke resistance than the Ni(300 mM) catalyst in a stability test at a low S/C ratio of 1 for 20 h.