Chemical reaction mechanism of Cu surface in aqueous H_2O_2:MD simulations using ReaxFF reactive force field

摘要

In order to study the thermochemical reaction mechanism of weakly rigid pure copper components in multi-energy field composite processing, Molecular dynamics (MD) simulations based on ReaxFF reactive force field was employed to investigate the interaction of the Cu surface in aqueous H_2O_2 and pure water. Research indicates that the main chemical substances on the Cu surface are Cu-H_2O and Cu-OH, when H_2O_2 is used as an oxidant. The H_2O or -OH of the above product have three sources: some come from H_2O molecules, some from H_2O_2 molecules and the other is formed by the exchange and recombination of H and O in H_2O and H_2O_2 molecules. According to the changes of H_2O and H_2O_2 molecules in the reaction process, H_2O molecules on the Cu surface have both molecular adsorption and dissociative adsorption, where molecular adsorption plays a dominant role even if the temperature increases. When the temperature rises, the dissociative adsorption of H_2O molecules and the oxidation of H_2O_2 molecules increases, and the formation of Cu-O bonds occurs. In contrast, there are only Cu-H_2O on the Cu surface in pure water. Comparative studies of different crystal phase of copper surfaces have also been carried out here, and the results of the interfacial reaction are also different. The study provides theoretical and technical support for the extreme fabrication of weakly rigid components.