Hydrotalcite-based CeNiAl mixed oxides for SO2 adsorption and oxidation

The impact of Ce on SO2 adsoption and oxidation was studied over a series of flower-like hydrotalcite-based CeNiAl mixed oxides. Combined with XRD, BET, pyridine chemisorption, CO2-TPD, XPS and H2-TPR results, it revealed that introduction of Ce into NiAlO generates new centres for oxygen storage and release, promotes the enhancement of Lewis acid strength, increases weakly and strongly alkaline sites, and increases ability for SO2 adsorption and oxidation. Furthermore, in situ Fourier transform infrared spectroscopy revealed that adsorbed SO2 molecules formed surface bidentate binuclear sulfate. Taken together, we propose that the addition of Ce4+ to NiAlO acts to improve this compound as major adsorbent for SO2.