Facile construction of Mn2O3@CeO2 core@shell cubes with enhanced catalytic activity toward CO oxidation

Highlights: • Mn₂O₃@CeO₂ core@shell cubes were fabricated by a facile three-step process. • CeO₂ shell thickness could be tuned by variying the feeding amount of Ce(NO₃)₃. • Mn₂O₃@CeO₂ core@shell cubes exhibted enhanced CO catalytic oxidation activity. • High activity can be attibuted to the synergistic action between Mn₂O₃ and CeO₂. -- Abstract: Heterogeneous core@shell nanostructures bring unique synergetic catalytic properties in comparison with their single-component materials, because the two-phase interface could render hybrid junctions with rich redox reactions. Herein, a series of Mn₂O₃@CeO₂ core@shell cubes with tunable CeO₂ shell thickness have been controllably synthesized by a facile multi-step process, which involved the annealing treatment of MnCO₃ precursor to produce Mn₂O₃ microcubes, followed by a refuxing process to deposit a uniform CeO₂ layer on the Mn₂O₃ surface. The CeO₂ shell was assembled by nanoparticles with sizes in the range of 2–10 nm, and the thickness could be facilely manipulated by changing the Mn/Ce molar ratios of reactants used in the synthetic process. The Mn₂O₃@CeO₂ core@shell cubes exhibited enhanced catalytic activity toward CO oxidation compared with both pure CeO₂ and Mn₂O₃, which was attributed to the synergistic interaction between CeO₂ and Mn₂O₃. Impressively, Mn₂O₃@CeO₂-0.1 sample with a proper CeO₂ thickness exhibited the highest catalytic performance, attaining 100% CO conversion at 220 °C.