Oriented growth of δ-MnO2 nanosheets over core-shell Mn2O3@δ-MnO2 catalysts: An interface-engineered effects for enhanced low-temperature methanol oxidation

•The pure manganese oxides Mn2O3@δ-MnO2 core-shell structures can be fine-manipulated via a novel synthesis method.•The synergistic effect of δ-MnO2 nanosheets and Mn2O3 microspheres is the key to enhance the deep methanol oxidation.•The Mn2O3@δ-MnO2 interface structure exhibited more Mn4+, well redox ability and active surface lattice oxygen.•Activity study revealed that the Mn2O3@δ-MnO2-8h catalyst has excellent activity for low-temperature methanol oxidation.