Understanding the key role of the surface structure of L11-ordered PtCu intermetallic electrocatalyst toward methanol oxidation reaction by dealloying methods

•Rough and smooth Pt shells were obtained by two dealloying methods.•Rough-NPs are more MA towards CH3OH, but the Cu is easily over-dissolved.•Smooth-NPs are less MA towards methanol, but Cu is more difficult to dissolve.•The MA of smooth-NPs is enhanced by the slight structural evolution of the surface.•The PtM i-NPs composed of different M (M = Mn, Fe, Cu, and Zn) have the similar conclusion.