Dissociative Adsorption of Azoles on Cu(111) Promoted by Chemisorbed O and OH

Abstract

We show by DFT calculations that chemisorbed O and OH species promote deprotonation of azole molecules on copper surfaces, as exemplified by imidazole, benzotriazole, and Cu(111). Deprotonation of benzotriazole on Cu(111) involves the N--H bond cleavage and is more exothermic than deprotonation of adsorbed imidazole that involves the C--H bond cleavage. The importance of molecular deprotonation is in higher stability of the resulting adsorption states, which increases the persistence of chemisorbed molecules on copper surfaces. In particular, deprotonated benzotriazole molecules are by about 1 eV more stable on O/Cu(111) and OH/Cu(111) compared to an adsorbed intact molecule on bare Cu(111).

Keywords: Density-functional-theory calculations, Dissociative chemisorption, Coadsorption, Corrosion inhibitors, copper