High-entropy single-atom activated carbon catalysts for sustainable oxygen electrocatalysis

The electrocatalytic oxygen reduction and evolution of molecular oxygen, known as oxygen electrocatalysis, is one of the most important reactions that are central to a range of energy and environmental technologies. While the current best-performing electrocatalysts remain dominated by precious metals, carbon-based systems provide a compelling alternative owing to their intrinsic sustainability and practical applicability. Here we show a design guided by theoretical calculations that pushes the activity boundaries of carbon electrocatalysts to an unprecedented level. The rationale is that incorporating high-entropy heteroatoms could effectively minimize the local symmetry to destabilize the π-electron network of graphitic carbons and avoid too strong or too weak binding energies for intermediate species of the oxygen reduction reaction and the oxygen evolution reaction. Accordingly, our catalyst embeds five metal single atoms—Fe, Mn, Co, Ni and Cu—and two sources of N, and it exhibits superior bifunctional activities in an alkaline environment that exceed the oxygen reduction reaction and evolution reaction performance of commercial Pt/C and RuO2 catalysts, respectively. Our work establishes electrocatalyst design principles that could open the door to sustainable solutions for critical green technologies such as fuel cells, batteries and water splitting.