Origin of the improved performance in lanthanum-doped silica-supported Ni catalysts

Dry‐reforming catalysts were prepared by supporting Ni nanoparticles (2–3 nm) on La‐doped silica. These materials display higher activity and stability in low‐temperature dry reforming (773 K) than Ni/SiO₂ or Ni/La₂O₃. The La‐doped silica‐supported catalysts were found to have exclusively lanthanum silicate at their surface rather than La₂O₃ and/or SiO₂. While an increasing amount of La was found to favor both CO₂ adsorption capacity and strength, it also influenced the hydrogen adsorption strength on nickel particles significantly, as evidenced by H₂ temperature‐programmed desorption analysis. Finally, CH₄ temperature‐programmed reduction analysis revealed that the CH₄ cracking threshold temperature varies in the order: Ni_bulk<Ni/La₃₄@SiO₂<Ni/La_2.1@SiO₂≪Ni/SiO₂<Ni/La₂O₃, which parallels the catalytic performance. Balancing the adsorption of CH₄, H₂, and CO₂ on supported Ni nanoparticles (2–3 nm) on La‐doped silica improves the catalytic performance of this low‐temperature dry‐reforming catalyst.