Hydrogen Yield from CO₂ Reforming of Methane: Impact of La₂O₃ Doping on Supported Ni Catalysts

Abstract

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.

Keywords

• Al₂O₃
• CO₂ reforming
• La₂O₃
• CH₄
• ZrO₂