Enhanced catalytic oxidation of toluene over heterostructured CeO2-CuO-Mn3O4 hollow nanocomposites

Abstract

Noble metal-free multicomponent heterostructured nanocomposites are excellent catalysts owing to their flexible compositions, synergistic effects, low cost, and complex nanostructures. Nevertheless, the rational design and synthesis of the multicomponent hollow nanospheres with controllable components, compositions, and structures remains a challenge. We demonstrated that by using carbon nanospheres (CNSs) as templates, a series of hollow ternary CexCu1−xO1+x-Mn3O4 (0 ≤x ≤ 1) nanospheres can be synthesized by a co-precipitation method, followed by the removal of CNSs. The ratio of Ce/Cu in the hollow CexCu1−xO1+x-Mn3O4 nanospheres can be adjusted simply by varying the feeding ratio of Ce and Cu salts. Particularly, hollow Ce0.5Cu0.5O1.5-Mn3O4 catalysts showed excellent catalytic activity and long-term stability, and full conversion of toluene was achieved at 225 °C. Systematic investigation of the catalytic activity and structural information of the ternary CexCu1−xO1+x-Mn3O4 catalysts revealed that the highly dispersed metal oxides, partial formation of solid solutions, and ultrathin hollow structures, all contributed to the catalytic activity. The simplicity and versatility of our approach hold great promise for the preparation of multicomponent heterostructured metal oxides with excellent catalytic activity.