Iridium-free high-entropy ruthenium-based oxides with activated lattice oxygen towards high efficient and durable acidic water oxidation†
Abstract
Ruthenium-based oxides are promising high-activity acidic OER catalysts to replace IrO2 but suffer from poor stability. Here, we report an Ir-free high-entropy (RuCrMnFeNi)O2 electrocatalyst with exceptional activity (212 mV@10 mA cm−2) and stability (100 h) in 0.5 M H2SO4. In PEM electrolyzers, it operates stably for 300 h at 200 mA cm−2. 18O labeling confirms a lattice-oxygen-mediated mechanism.