Molecular Dynamic Simulation of Ni-Al Alloy-H2O Reactions Using the ReaxFF Reactive Force Field

Abstract

Hydrogen as clean energy can effectively solve the problems of fossil energy shortage and environmental pollution. However, traditional methods of H2 production are generally lacking in application value. The procedure for manufacturing H2 by a reaction between active metals and H2O has received wide attention due to its high efficiency. Profound insights into the mechanism and influencing factors of H2 production from active metals are insufficient. The ReaxFF reaction force field module of the Amsterdam Modeling Suite (AMS) is applied in this paper to simulate the reaction of Ni-Al alloys with H2O. It reveals the reaction route of H2 production at the atomic level. The calculation results show that Al is the most critical active site. Moreover, the H2 production capacity of the alloy varies with the crystal structure and atomic ratio. The H2 production rate decreases due to the influence of the water solvation layer and surface coverage. Oxygen reduces the H2 production capacity because oxygen reduces the active sites for H2O adsorption by forming a stable oxide layer with Al.