The effect of the oxidation states of supported oxides on catalytic activity: CO oxidation studies on Pt/cobalt oxide

The strong metal–oxide interaction of platinum nanoparticles (PtNPs) deposited on two types of cobalt oxides, CoO and Co3O4, was investigated using CO oxidation. Two different sizes of PtNPs as well as arc-plasma-deposited (APD) PtNPs without a capping layer were used to reveal the effect of metal–oxide interfaces on catalytic activity. An enhanced catalytic activity was observed on the PtNPs on the Co3O4 substrate, which was ascribed to the reducible support and to the interfacial sites.