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

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.