DFT study on bimetallic Pt/Cu(1 1 1) as efficient catalyst for H 2 dissociation

•The double-layer Pt on top of Cu(1 1 1) is found to be energetically favorable.•The CO saturation coverage on double-layer Pt/Cu(1 1 1) (40%) is found to be lower than that of pure Pt (about 75%).•The dissociation barrier from H2 to H is less than 0.4 eV under the saturation coverage of CO on double-layer Pt/Cu(1 1 1).