Effect of H2S on the corrosion-fouling behaviors of Cu-base surface

Abstract

Based on the First-principles method of density functional theory (DFT), the adsorption of H2S on the primary growth surface (001)(111)(110) of Cu-base was investigated. The results demonstrate that the stable adsorption position of H2S on Cu(001)(111)(110) surface is t-parallel, b-H-down-c and h-H-down-c, respectively. And the corresponding adsorption energy is the minimum of −0.580 eV, −0.560 eV, −0.527 eV. After doping Zn in Cu, b-parallel, b-parallel and h-H-down-p are the stable adsorption position of H2S on Cu–Zn(001)(111)(110) surface. More chemical bonds form on adsorption sites of Cu and Cu–Zn substrate. Crystal structure of Cu doping Zn becomes unstable and easy to be corroded. Additionally, the experimental results reveals that copper shows better corrosion resistance of H2S than that of brass. Trends of fouling deposit curve of copper and brass are similar while the fouling is prone to deposit on the surface of brass after H2S corrosion. The consequences evidence that the fouling deposition can be influenced by the corrosive surface of materials and the fouling is prone to deposit on the corrosive pits and cracks. Furthermore, the crystal form of calcium carbonate on the surface of brass and copper after H2S corrosion is primarily aragonite and calcite. The corrosion products can promote the fouling adhesion.