Adsorption behavior of HCOOH on the crystal surfaces of Cu(111) and (100)

In order to investigate the adsorption mechanism of formic acid (HCOOH, FA) on the surface of Cu substrate during soldering, the adsorption energies of formic acid gas at the Top, Bridge and Fcc sites of Cu(111) and (100) planes and the surface energies of Cu(111) and (100) were identified by employing first-principles method relied on density functional theory (DFT). These findings demonstrate that the adsorption energy of HCOOH is the highest at the Bridge site of (100) plane, and the adsorption type is physical adsorption, which indicates that the HCOOH molecule is more easy to adsorb at the Bridge site of (100) plane. In addition, the surface energy of (100) plane is higher than that of (111) plane, revealing that (100) plane is more stable than that of (111) plane.