Stabilizing High-Entropy Substrates and Tailoring Interfacial Water: High-Valent Pt Single Atoms Drive Durable Propylene Epoxidation
Electrochemical propylene epoxidation offers a sustainable route to propylene oxide (PO), but achieving high selectivity and stability under industrial current densities remains challenging. Herein, we report a high entropy amorphous CoFeNiCrMnBOx borate loaded with high valence Pt single atoms catalyst (a-Pt-HEBO) for stable bromine radical-mediated propylene epoxidation reaction (BrPOR). The high-entropy amorphous structure reshapes the interfacial hydrogen-bonding network and enriches free water, substantially lowering the energy barrier for water dissociation. Meanwhile, the strong electronic interactions between the coordinatively unsaturated, high-valence single Pt atoms and the substrate effectively prevent transition metal dissolution at high anodic potentials. The catalyst achieved 82.1% Faraday efficiency of PO at an industrial grade current density of 100 mA cm-2, and demonstrated excellent industrial application stability in up to 500 h of continuous test and within a scaled-up electrolyzer (4 × 4 cm2). This work provides a design for high-entropy catalysts in halogen-mediated electrosynthesis and a viable pathway toward carbon-neutral PO production.