Mechanistic understanding of hydrogenation of acetaldehyde on Au(111): A DFT investigation

► DFT calculations are used to model hydrogenation reaction of acetaldehyde on atomic hydrogen pre-covered Au(111). ► The mechanism contains hydrogenation, coupling, and disproportionation reactions. ► Rearrangement and diffusion of surface species are facile at reaction condition. ► Activation barriers for elementary steps match with the experimental results.