Beyond the Gold-Hydrogen Analogy: Doping Gold Cluster with H-atom-O2 Activation and Reduction of the Reaction Barrier for CO Oxidation

The gold hydrogen analogy is well established in terms of analogous chemistry exhibited by gold and hydrogen atoms. A step beyond this analogy is demonstrated here by showing that the replacement of a Au atom with a H-atom in a gold cluster can lead to considerable enhancement in its reactivity. The present computational study reveals that while the closed-shell neutral pristine gold cluster Au-8 can bind only weakly with an O-2 molecule, its doped counterpart Au7H shows remarkable enhancement in its binding with molecular oxygen. It also shows an increment in O-O bond length and a red shift in vibrational frequency, indicating the activation of the O-2 molecule. Furthermore, the H-doped gold cluster reduces the barrier height for the environmentally important CO oxidation reaction as compared to the pristine cluster. These observations may spur further studies in the design of a cost-effective and efficient catalyst by doping gold clusters with a cheaper element like hydrogen.