New Ni-based quaternary disk-shaped catalysts for low-temperature CO₂ methanation: Fabrication, characterization, and...

Ni-based quaternary disk catalysts were manufactured for low-temperature CO₂ methanation reactions, and the reaction activity was examined with respect to the thermal treatment conditions. By applying varying reduction and combustion treatments, the same catalysts were compared, and the Ni oxidation conditions and physical features were confirmed through X-Ray diffraction, scanning electron microscopy, and energy dispersive X-ray analyses. In addition, oxygen adsorption/desorption changes were measured by temperature-programmed reduction after pre-treating with oxygen and hydrogen. The reduction treatment catalyst showed a conversion of 20% at 280 °C, and the 70% calcined catalyst did not form a NiO crystalloid. The activation of the catalyst increased because of NiO movement on the catalyst surface, which enabled easy transformation to metallic Ni. The prepared catalyst is a highly reactive, yet stable, candidate for practical catalytic CO₂ methanation.