Facile synthesis of Mn2O3 hollow and core–shell cube-like nanostructures and their catalytic properties

• Hollow Mn2O3 nanostructures were synthesized by a polyol-based precursor route.
• The formation mechanism of MnCO3 precursor hollow nanostructures was proposed.
• Mesoporous Mn2O3 power was prepared through calcination of MnCO3 precursor.
• CO catalytic oxidation of Mn2O3 hollow and core–shell structures was explored.
• Mesoporous hollow Mn2O3 cubes exhibited a higher catalytic activity.

Manganese carbonate (MnCO3) hollow cube-like nanostructures were synthesized via a facile polyol process and then thermal converted to phase-pure manganese oxide (Mn2O3). Based on the structural analysis of MnCO3 precursor obtained at different reaction times, a mechanism of inside-out Ostwald ripening was proposed to account for the formation of the hollow nanostructures. An annealing treatment at 500 °C with a ramping rate of 3 °C min−1 was utilized to convert the MnCO3 precursor into Mn2O3. The manganese oxide powder products possessed mesoporosity and essentially preserved the pristine morphology of the MnCO3 precursor. The products were characterized by X-ray powder diffraction (XRD), and field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), Thermal gravimetric analyze (TGA), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET). Furthermore, relative to Mn2O3 core–shell cube-like microstructures, the mesoporous hollow cubes exhibited a higher catalytic activity towards CO oxidation.