Chemical Activities of Fresh Surfaces of 1B-4B Metals and Alloys.

Abstract

Chemical activities of fresh surfaces of Cu, Zn, Al, Sn and Pb and copper-base alloys were investigated at room temperature. The fresh surfaces were formed by scratching under high vacuum conditions. Fresh copper surfaces exhibited the highest chemical activity among 1B∼4B metals used. On the other hand, no organic compound chemisorbed on fresh lead surfaces. Judging from the chemisorption activities of organic compounds, the activities of fresh metal surfaces decreased in the following order; Pb < Sn< Al< Zn< Cu. The order of the adsorption activity of organic compounds on the fresh copper surfaces was : ether < sulfide <oleffin and benzene < iodide. The order can be explained in terms of softness of functional groups. XPS measurements revealed that lead was concentrated on scratched surface of Cu-Pb alloys. Chemical activity of Cu-Pb alloy was similar to that of Pb. This can be explained by the concentrated Pb on the fresh surface. The chemical activity of copper-alloys for propyl iodide decreased by the addition of zinc or tin to copper. It was concluded that the chemical activity of fresh surfaces was controlled by chemical properties of metals and the functional groups to be adsorbed.