CO oxidation and CO-PROX reactions over Au catalysts supported on different metal oxides: a comparative study

Comparative research about the total CO oxidation and CO-PROX reaction over Au-based materials supported on different oxides was carried out. CeO2, MnO2, TiO2 and SiO2 with nominal content of 1 wt.% of Au were prepared by a modified deposition–precipitation method. The samples were characterized by XRF, XRD, BET, H2-TPR and HR-TEM techniques. Catalytic results of the CO oxidation in the absence and presence of hydrogen showed that the supports and Au/SiO2 were inactive. For the Au/MnO2 and Au/TiO2 samples, CO conversion was lower in the presence of H2, while for Au/CeO2 the conversion of CO in the CO-PROX was higher compared to that in the total CO oxidation. These results show that the impact of H2 on CO oxidation over Au catalysts is dependent on the charactersitics of the materials that, in turn, are influenced by the nature of the support.