Enhanced interaction of molecular oxygen with amino acid complexes of silver and gold clusters

Abstract

<span style="font-size:9.0pt;mso-bidi-font-size: 12.0pt" lang="EN-US">Density functional theory calculations have been carried out to study the effect of amino acid adsorption on the reactivity of silver and gold clusters with molecular oxygen. It is found that the amino acids glycine and alanine form stable complexes with both Ag₄ and Au₄ clusters. However, the extent of interaction is more in the case of the Au₄ cluster, as reflected from the increase in binding energy in the amino acid Au₄ complexes. Our results confirm that the adsorption of amino acids glycine and alanine enhances the reactivity of Ag₄ and Au₄ clusters towards O₂ molecule. The enhanced reactivity of O₂ molecule towards the amino acid metal cluster complexes is manifested by an increase in the O₂ binding energy and a decrease in the M–O (M = Ag, Au) bond length. Moreover, it is found that the co-adsorption of amino acids and O₂ molecule on the Ag₄ and Au₄ clusters is cooperative.

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