Mitigating hydrogen embrittlement in high-entropy alloys for next-generation hydrogen storage systems

Green hydrogen can potentially reduce carbon emissions in several types of automotive, transport and energy industries. However, effective handling of hydrogen during generation, storage, transportation, and distribution poses significant challenges concerning the materials aspect as they are prone to failure. One of the primary reasons for the failure of material is hydrogen embrittlement (HE). This review focuses on developing a new alloy system namely high-entropy alloys (HEAs) to improve and promote microstructure modifications and enhance mechanical properties. Researchers have developed many high-entropy alloys (HEAs) for handling hydrogen to overcome the failure faced by conventional materials. The primary cause of HE in materials is the absence of phase stability and crystal structure changes during hydrogen-induced environments. However, increasing the materials' ductility is more likely to reduce HE failures. Thus, FCC crystal structures are preferred for hydrogen storage materials. Adding multiple elements to increase the entropy level, which supports high-phase stability in all environmental conditions, is an important reason for using HEAs to mitigate HE failures.