Three different alumina-based Ni, Cu, Co oxide catalysts with metal loading of 10 wt %, and labeled 10Ni⁻Al, 10Co⁻Al and 10Cu⁻Al, were prepared by microwave-assisted solution combustion. Their morphological, structural and surface properties were deeply investigated by complementary physico-chemical techniques. Finally, the three materials were tested in CO oxidation used as test reaction for comparing their catalytic performance. The 10Cu⁻Al catalyst was constituted of copper oxide phase, while the 10Ni⁻Al and 10Co⁻Al catalysts showed the presence of "spinels" phases on the surface. The well-crystallized copper oxide phase in the 10Cu⁻Al catalyst, obtained by microwave synthesis, allowed for obtaining very high catalytic activity. With a CO conversion of 100% at 225 °C, the copper containing catalyst showed a much higher activity than that usually measured for catalytic materials of similar composition, thus representing a promising alternative for oxidation processes.
Keywords: CO oxidation; Co-oxide catalysts; Cu; alumina-based Ni; catalytic activity; microwave-assisted solution combustion.