High Entropy Intermetallic-Oxide Core-Shell Nanostructure as Superb Oxygen Evolution Reaction Catalyst

Designing active, stable, yet low cost electrocatalysts for the oxygen evolution reaction (OER) is pivotal to the next generation energy storage technology. However, conventional OER catalysts are of low electrochemical efficiency while the state-of-the-art nanoparticle-based catalysts require mechanical supports, thereby limiting their wide deployment. Here, it is demonstrated that, due to the excellent corrosion resistance of the Fe-Co-Ni-Cr-Nb high entropy intermetallic Laves phase, fabricating a high entropy bulk porous nanostructure is possible by dealloying the corresponding eutectic alloy precursor. As a result, a core-shell nanostructure with amorphous high entropy oxide ultrathin films wrapped around the nanosized intermetallic ligaments is obtained, which together, exhibits an extraordinarily large active surface area, fast dynamics, and superb long-term durability, outperforming the existing alloy- and ceramic-based OER electrocatalysts. The outcome of the research suggests that the paradigm of "high entropy" design can be used to develop high performance catalytic materials.