First-principles study of hydrogen separation behavior in vanadium-aluminum alloys

Vanadium (V)-based alloys have emerged as promising materials for hydrogen (H) separation applications. In this study, we investigate the influence of aluminum (Al) doping on the overall properties of V-based alloys to gain a deeper understanding of their practical prospects. Our results highlight that Al doping induces decreased ductility, and H atoms tend to occupy positions close to V atoms due to the repulsive interactions with Al atoms. Higher Al concentrations lead to increased solution energies and reduce the number of available sites for H atoms, impacting the efficiency of hydrogen separation. While this mitigates the issue of hydrogen embrittlement, V-Al alloys with high Al content may require the addition of other components, such as Mn, to enhance hydrogen diffusion and ductility. Our findings reveal the complex relationship between Al doping levels in V alloys and H dissolution and diffusion, providing valuable insights for the design and optimization of V-Al alloys for H separation applications.