Preservation from easy aerobic Cu(0) oxidation in Cu nanoparticles (NPs) is of interest for electronic, sensing, optical and catalytic properties. An anti-galvanic (AG) method is presented here for this purpose. Remarkably, alloying CuNPs with AuNPs or AgNPs followed by exposure to air only leads to Cu(0) oxidation to Cu(I) in AgCu alloyed NPs, whereas Cu(0) is not oxidized in AuCu alloyed NPs in which Au(I) forms. This result is also verified by “click” catalysis experiments.