Liquid-Phase Ethanol Oxidation and Gas-Phase CO Oxidation Reactions over M Doped (M = Ag, Au, Pd, and Ni) and MM′ Codoped CeO₂ Nanoparticles

Figure 7

UV-visible absorption spectra of the ethanol oxidation with no catalyst, undoped CeO₂, M doped (M = Ag, Au, Pd, and Ni) and MM′ codoped (Ag/Au (a), Ni/Au (b), Pd/Au (c), and Ni/Pd (d)) CeO₂ catalysts at 80°C for 5 days. The left inset in (a) shows the magnified spectra of the grey shadowed region. The right inset in (a) shows the UV-Vis absorption spectra of ethanol oxidation with the 5 mol.% Au doped CeO₂ catalyst at 80°C according to the reaction time.

(a)

(b)

(c)

(d)