Gold supported on metal-doped ceria catalysts (M = Zr, Zn and Fe) for the preferential oxidation of CO (PROX)

A series of ceria oxides doped with 10 mol.% of Zr, Zn and Fe have been prepared by a pseudo sol–gel method throughout the thermal decomposition of the corresponding metallic propionates. With these supports, 1 wt.% gold catalysts were prepared by the deposition–precipitation method. All the solids were characterized by means of XRF, N2 adsorption, XRD, Raman spectroscopy and SEM techniques, and their catalytic activity toward preferential oxidation of CO (PROX) reaction tested. The results showed solid solution when doping with Zr and Fe and ZnO surface segregation in the case of Zn. We demonstrate that gold dispersion depends on not only the oxygen vacancy concentration but also the nature of the doping agent. Finally, the catalytic activity was highly promoted by gold in all cases, being the doped gold catalysts more active than Au/CeO2 at low temperature.