DFT Study of Hydrogen Evolution Reactions of Water Molecule with In7 and In6Al Clusters

Abstract

The specific process of hydrogen generation by the reaction of In7 and In6Al clusters with H2O molecules is explored through density functional theory in this study. Based on the prediction of the lowest energy structure of In7 and In6Al clusters, the geometric and electronic structures of In7@H2O and In6Al@H2O are obtained by using the dispersion-corrected density functional theory B3LYP-D3. The corresponding reaction paths are constructed according to the transition states in the searched reactions. Then we discuss the reaction path, energy barrier and reaction energy release. The results show that both In7 and In6Al clusters can react with H2O molecules and release hydrogen. Both reactions are exothermic reactions, and the structure of the reaction product are very similar. The comparison of adsorption energy, energy barrier and reaction release energy show that the Al-doped In7 cluster can significantly improve its ability to react with H2O and reduce the energy barrier that has to be overcome for the reaction process. The generated H2 exists on the cluster surface in the form of physical adsorption, which is judged by the adsorption energy, the distance between the H2 molecule and the cluster surface, and the interaction region indicator.