High-entropy perovskite oxides promise better catalysts

• Oxygen evolution reaction (OER) is an important reaction enabling green production of hydrogen by water electrolysis. • High-entropy perovskite oxides offer exceptionally high catalytic activity for the OER. • Perovskite transition metal oxides promise high activity and tunability of electrochemical properties. • High-entropy perovskite oxides are promising catalytic materials that avoid use of precious metals.