Effects of defective nanostructured alumina supports on the syngas production by tri-reforming of methane

This work aims to evaluate the influence of defective nanostructured alumina supports on the catalytic performance of the solids in the TRM reaction. The synergistic effects between NiPt nanoparticles on the nanostructured alumina support is also examined. Depending on the promoter added to the nanostructured alumina i.e., Zn, Mg or La, stable spinel phases or solid solutions with abundant intrinsic oxygen defects are formed. For NiPt/Al₂Zn_xO_y and NiPt/Al₂La_xO_y, enriched PtO_x and NiO nanoparticles microenvironments surrounding the defective support facilitate oxygen diffusion within the crystal lattice to the NiPt surface, which appeared to be the reason for the activity of the solids in the reaction. The NiPt/Al₂Mg_xO_y formed a NiO-MgO solid solution and out layer spinel phases, in which the presence of lattice oxygen species and extended defects helped by the accessible NiPt alloy on the support surface gave a strong metal-support interaction. This results in an improvement of the methane and CO₂ conversions of 75 and 95 % at H₂/CO ratio of 1.3.