Bringing Order to Chaos in High-Entropy Electrocatalysts.

High-entropy materials (HEMs) have emerged as a transformative platform for electrocatalysis. Their appeal lies in the vast compositional versatility enabled by the combination of five or more elements, which generates a rich diversity of atomic configurations and surface sites ideally suited for complex multistep reactions. Recent years have witnessed explosive growth in the development of HEMs across diverse material classes and their application to a wide range of electrochemical reactions. Yet significant challenges remain to fully harness their capabilities while managing their intrinsic structural and chemical complexity. Advancing the field requires exploring compositional space, pinpointing reaction sites, and achieving atomic-level control of surface composition and organization. Much remains to be done, calling for breakthroughs in materials design, characterization, and synthesis strategies and technologies. Ultimately, as highlighted here, beyond electrocatalytic applications, HEMs embody a new paradigm in materials discovery, linking precise engineering, correlative multimodal characterization, and high-throughput experimentation and computation.