Quantum-Chemical Simulation of the Adsorption of OH – Ions on Au(111)

Based on the cluster model of the metal surface, the OH– ion interaction with the gold surface is studied by the density functional method. The geometrical and energy characteristics of this interaction are assessed. The adsorption of the OH– ion in its “bridge” position with the angle of 117° between the normal to the surface and the O–H bond is the most advantageous as regards energy. When adsorbed, the ion loses about half of its charge. The involvement of the adsorbed OH– ion and gold atoms the nearest to it in the formation of molecular orbitals of this system is assessed. The contribution to their formation is made preferentially by the p orbitals of the oxygen atom and the d orbitals of gold.