Effect of active phase precursor on structural, textural and catalytic properties of the model $NiO_x/CeO_2$ system active in dry reforming of methane

The current paper is devoted to the synthesis of ceria-supported nickel-based catalysts starting from different precursors of the nickel active phase. Thermal decomposition of metal-containing precursors, deposited onto stable supports by dry impregnation, belongs to the industrially preferred, simple ways of catalyst preparation. The synthesized series of $NiO_x/CeO_2$ catalysts have been tested in dry methane reforming (DMR), in which two greenhouse gases, i.e., $CO_2$ and $CH_4$, are simultaneously converted into syngas. Both reaction progress and stability of the catalyst strongly depend on nickel speciation, which in turn can be determined by the nature of the chosen precursor. Contrary to relatively many studies focused on the importance of synthetic methods and conditions on nickel speciation, the effect of precursor nature on structural, textural, and functional properties of catalytic systems has neither been discussed much nor fully understood. The main goal of this paper was to elucidate the effect of precursors on the properties of $NiO_x/CeO_2$. Consequences of the use of various nickel precursors (simple inorganic salts, organometallic complexes, and chelates) have been analyzed in detail from the viewpoint of their beneficial influence on the catalytic performance of $NiO_x/CeO_2$ system (containing 3 wt. % of Ni) tested in DMR.