Functional Improvement of NiO x /CeO 2 Model Catalyst Active in Dry Methane Reforming via Optimization of Nickel Content.

The valorization of greenhouse gases, especially when focused on carbon dioxide, currently belongs to the main challenges of pro-environmental chemical processes. One of the important technologies in this field is dry methane reforming (DMR), leading to the so-called synthesis gas (CO + H₂). However, to be efficient and economically viable, an active and stable catalyst is required. Ni-based systems can be recommended in this regard. This research aimed to investigate how nickel content can influence the activity of model NiO_x/CeO₂ catalysts in DMR. A series of NiO_x/CeO₂ samples of various nickel loadings (0–10 wt.%) were prepared through dry impregnation. The obtained samples were characterized through XRD, RS, N₂-BET, DRIFT, SEM, UV/Vis-DR, and XPS. Nonlinear changes in surface properties of the investigated samples with increasing nickel concentration were found. The observed changes are mirrored both in the determined nickel speciation and in the corresponding catalytic activity. The highest activity was found for the catalyst containing 3 wt.%. of nickel. [ABSTRACT FROM AUTHOR]