The first-principle study of the iodine-modified silver surfaces

The properties of the I-modified Ag(1 1 1), (1 0 0) and (1 1 0) surfaces ar e studied via the first-principle local density functional calculation with the ultrasoft pseudopotential and the generalized gradient approximation. The preferred adsorption site, relaxation of the surface structure, adsorpt ion energy, work function change and changes of the properties with the cov erage as well as total density of state are investigated. The most energeti cally favorite adsorption site is hollow site on the (1 0 0) surface in our study. Strong interaction between the iodine atom and the surface and tran sfer of electronic charges from the silver surface to the iodine atom are o bserved. The function of the iodine atom in the partial oxidation of the me thanol is discussed based on our results. (C) 2001 Elsevier Science B.V. Al l rights reserved.