Designing Highly Efficient Cu(2)O-CuO Heterojunction CO Oxidation Catalysts: The Roles of the Support Type and Cu(2)O-CuO Interface Effect

In this work, a series of Cu(2)O/S (S = α-MnO(2), CeO(2), ZSM-5, and Fe(2)O(3)) supported catalysts with a Cu(2)O loading amount of 15% were prepared by the facile liquid-phase reduction deposition–precipitation strategy and investigated as CO oxidation catalysts. It was found that the Cu(2)O/α-MnO(2) catalyst exhibits the best catalytic activity for CO oxidation. Additionally, a series of Cu(2)O-CuO/α-MnO(2) heterojunctions with varied proportion of Cu(+)/Cu(2+) were synthesized by further calcining the pristine Cu(2)O/α-MnO(2) catalyst. The ratio of the Cu(+)/Cu(2+) could be facilely regulated by controlling the calcination temperature. It is worth noting that the Cu(2)O-CuO/α-MnO(2)-260 catalyst displays the best catalytic performance. Moreover, the kinetic studies manifest that the apparent activation energy could be greatly reduced owing to the excellent redox property and the Cu(2)O-CuO interface effect. Therefore, the Cu(2)O-CuO heterojunction catalysts supported on α-MnO(2) nanotubes are believed to be the potential catalyst candidates for CO oxidation with advanced performance.