The mechanism of water decomposition on surface of aluminum and gallium alloy during the hydrogen production process: A DFT study

Abstract

The efficient hydrogen-production through the Aluminum-water reaction has become a prominent subject of interest. The impediment encountered in the reaction can be effectively alleviated by Aluminum-based alloy. In this study, density functional theory (DFT) was utilized to explore the mechanism of water decomposition stage on the surface of aluminum and gallium alloy (AGA). Through surface reaction calculations of 12 stable AGA configurations, it was gradually revealed that the optimal alloy ratio was gallium-to-aluminum at 3.5:1. Analysis of the density of states (DOS) indicated that the presence of gallium amplified the activity of surface aluminum. Moreover, frontier orbital theory and charge density maps confirmed that, due to the weak interaction between Ga and ions, the presence of H2 inhibited Ga passivation, thereby enhancing the reactivity of AGA. This paper provided valuable insights into the surface reaction mechanisms of AGA using DFT, offering theoretical support for hydrogen production processes.