Potential origin of natural vanadium hydride in the Earth's shallow mantle

Metal hydrides have emerged as promising candidates for energy storage in clean hydrogen systems. While these materials are typically synthesized under controlled laboratory conditions, naturally occurring vanadium hydride (VH₂) has been identified in mantle-derived igneous rocks, suggesting that it may from in geological environments. In this study, we investigate the formation mechanisms and melting behavior of vanadium hydride under mantle conditions by integrating high-pressure experimental techniques with molecular dynamics simulations. Our experimental results demonstrate that hydrous minerals, such as Mg(OH)₂, can react with elemental vanadium (V₀) at elevated temperatures (1000–1500 ℃) and pressures (0.8–3 GPa) to form vanadium hydride. Molecular dynamics simulations further reveal that the melting temperature of VH₂ at 1 GPa ranges between 1400 and 1500 ℃. These findings suggest that natural vanadium hydride may originate in the Earth's shallow mantle and subsequently migrate to the crust or surface through magmatic processes. This study provides a theoretical basis for further exploration of naturally occurring metal hydrides and supports the development of synthetic metal hydrides for solid-state hydrogen storage.