Stability and Activity of Rhodium Promoted Nickel-Based Catalysts in Dry Reforming of Methane

The rhodium oxide (Rh2O3) doping effect on the activity and stability of nickel catalysts supported over yttria-stabilized zirconia was examined in dry reforming of methane (DRM) by using a tubular reactor, operated at 800 degrees C. The catalysts were characterized by using several techniques including nitrogen physisorption, X-ray diffraction, transmission electron microscopy, H-2-temperature programmed reduction, CO2-temperature programmed Desorption, and temperature gravimetric analysis (TGA). The morphology of Ni-YZr was not affected by the addition of Rh2O3. However, it facilitated the activation of the catalysts and reduced the catalyst's surface basicity. The addition of 4.0 wt.% Rh2O3 gave the optimum conversions of CH4 and CO2 of similar to 89% and similar to 92%, respectively. Furthermore, the incorporation of Rh2O3, in the range of 0.0-4.0 wt.% loading, enhanced DRM and decreased the impact of reverse water gas shift, as inferred by the thermodynamics analysis. TGA revealed that the addition of Rh2O3 diminished the carbon formation on the spent catalysts, and hence, boosted the stability, owing to the potential of rhodium for carbon oxidation through gasification reactions. The 4.0 wt.% Rh2O3 loading gave a 12.5% weight loss of carbon. The TEM images displayed filamentous carbon, confirming the TGA results.

Automated summary

The impact of rhodium oxide (Rh2O3) doping on the activity and stability of nickel catalysts supported over yttria-stabilized zirconia in dry reforming of methane (DRM) was studied at 800 degrees C using various characterization techniques. The addition of 4.0 wt.% Rh2O3 enhanced the activation of the catalysts and reduced the surface basicity, leading to optimal conversions of CH4 and CO2 of around 89% and 92%, respectively. The incorporation of Rh2O3 in the range of 0.0-4.0 wt.% loading improved DRM and reduced the reverse water gas shift effect, resulting in increased stability by decreasing carbon formation on the catalysts.