Reactivity and Catalytic Activity of Hydrogen AtomChemisorbed Silver Clusters.

Metalclusters of silver have attracted recent interest of researchersas a result of their potential in different catalytic applicationsand low cost. However, due to the completely filled d orbital andvery high first ionization potential of the silver atom, the silver-basedcatalysts interact very weakly with the reacting molecules. In thecurrent work, density functional theory calculations were carriedout to investigate the effect of hydrogen atom chemisorption on thereactivity and catalytic properties of inert silver clusters. Ourresults affirm that the hydrogen atom chemisorption leads to enhancementin the binding energy of the adsorbed O2molecule on theinert silver clusters. The increase in the binding energy is alsocharacterized by the decrease in the Ag–O and increase in theO–O bond lengths in the case of the AgnH silver clusters. Pertinent to the increase in the O–Obond length, a significant red shift in the O–O stretchingfrequency is also noted in the case of the AgnH silver clusters. Moreover, the hydrogen atom chemisorbedsilver clusters show low reaction barriers and high heat of formationof the final products for the environmentally important CO oxidationreaction as compared to the parent catalytically inactive clusters.The obtained results were compared with those of the correspondinggold and hydrogen atom chemisorbed gold clusters obtained at the samelevel of theory. It is expected the current computational study willprovide key insights for future advances in the design of efficientnanosilver-based catalysts through the adsorption of a small atomor a ligand. [ABSTRACT FROM AUTHOR]