Optimizing LaNiO₃ Perovskite as Catalyst Precursor for the Revalorization of Biogas by Dry Reforming of Methane

The Dry Reforming of Methane (DRM) is an efficient route to produce syngas (which is the feedstock for the production of synthetic fuels via the Fischer-Tropsch process) or hydrogen from methane and carbon dioxide. This work evaluates several nickel-based perovskite-type mixed oxides (La_xNiO₃, La_0.8Ni_0.9M_0.1O₃ (M = Co, Fe and Mn) and La_0.8Ni_1-yCo_yO₃) as precursors of the active phase (Ni) for the DRM reaction. Although La_0.8NiO₃ yields slightly smaller Ni particles after reduction, it promotes the accumulation of a significant amount of carbonaceous material during DRM. Partial Ni substitution with Co, Fe and Mn improves redox stability, with the La_0.8Ni_0.75Co_0.25O₃ formulation being the most effective for removing the carbonaceous deposits under a 25% CH₄, 25% CO₂ (50% He) reactant atmosphere. However, when this formulation is used as a catalyst precursor for DRM under more realistic conditions (i.e., employing a feed that simulates real biogas), CH₄ conversion and H₂ yield decrease, and the carbon accumulated increases due to the greater influence of the parallel reactions. As a positive sign for future applications or research, under these conditions, the addition of 0.5% O₂ to the feed and the use of a CO₂ regeneration step decreased the amount of carbonaceous material deposited.