Surface structure and catalytic properties of MoO3/CeO2 and CuO/MoO3/CeO2

► Molybdena monolayer-modified CeO2 increases the dispersion capacity of copper oxide. ► MoO3/CeO2 samples with different MoO3 loadings have different structures. ► After the addition of CuO, the structures of molybdena species change significantly. ► The surface acidity is related to the molybdena species structures tightly. ► The active sites of CuO/MoO3/CeO2 in ''NO + NH3 + O2'' reaction are proposed.