LaNi^sub 1-x^Mn^sub x^O^sub 3^ perovskite-type oxides as catalysts precursors for dry reforming of methane

A series of ternary perovskite-type oxides LaNi1-xMnxO3 (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) were synthesized by the sol–gel resin method in propionic acid, producing solids solutions of perovskite-type structures with crystallite sizes between 15–20 nm. The LaNi1-xMnxO3 catalysts were thoroughly characterized and tested in the catalytic dry reforming of methane (DRM) reaction. It was observed that the presence of Mn in the perovskite-type oxide increases the Ni3+ to Ni0 reduction temperature giving rise to formation of Ni0 nanoparticles on the MnOx-La2O3 matrix. The LaNi1-xMnxO3 with x ≤0.8 showed higher activities and selectivity’s towards syngas during the CH4–CO2 reforming, due to in situ formation of highly dispersed Ni0-metallic nanoparticles on the La2O2CO3-MnO-Mn2O3 solid matrix responsible for the high activity and high resistance to carbon buildup on the catalyst surface.