Hydrogen yield from co₂ reforming of methane: Impact of la₂o₃ doping on supported ni catalysts

Development of a transition metal based catalyst aiming at concomitant high activity and stability attributed to distinguished catalytic characteristics is considered as the bottleneck for dry reforming of methane (DRM). This work highlights the role of modifying zirconia (ZrO₂) and alumina (Al₂O₃) supported nickel based catalysts using lanthanum oxide (La₂O₃) varying from 0 to 20 wt% during dry reforming of methane. The mesoporous catalysts with improved BET surface areas, improved dispersion, relatively lower reduction temperatures and enhanced surface basicity are identified after La₂O₃ doping. These factors have influenced the catalytic activity and higher hydrogen yields are found for La₂O₃ modified catalysts as compared to base catalysts (5 wt% Ni-ZrO₂ and 5 wt% Ni-Al₂O₃). Post-reaction characterizations such as TGA have showed less coke formation over La₂O₃ modified samples. Raman spectra indicates decreased graphitization for La₂O₃ catalysts. The 5Ni-10La₂O₃-ZrO₂ catalyst produced 80% hydrogen yields, 25% more than that of 5Ni-ZrO₂. 5Ni-15La₂O₃-Al₂O₃ gave 84% hydrogen yields, 8% higher than that of 5Ni-Al₂O₃. Higher CO₂ activity improved the surface carbon oxidation rate. From the study, the extent of La₂O₃ loading is dependent on the type of oxide support.