Electrosynthesis of Chlorine Oxidant From Direct Seawater Electrolysis via High‐Entropy Intermetallic

Direct saline water electrolysis technology can generate reactive chlorine species to achieve environmental remediation and disinfection. However, the high-concentration chloride ions in the electrolyte tend to cause corrosion to the catalytic system, leading to the attenuation of catalyst activity and the decline of stability. Herein, the filtered cathodic vacuum arc (FCVA) co-deposition technology was adopted to successfully construct a MnFeCoNiCu high-entropy catalytic current collector (MFCNC). Relying on the synergistic effect among elements, this high-entropy structure exhibits excellent salt tolerance and is compatible with the reactive chlorine electrolysis systems. It enables the electrochemical synthesis of reactive chlorine while realizing hydrogen production. Long-term stability tests show that the catalytic current collector can operate stably for more than 100 h during the electrolysis process. Moreover, it can significantly reduce the overpotential of the catalytic reaction, optimize the reaction process from a kinetic perspective, and effectively lower the energy consumption of the system. Additionally, the MFCNC has dual application values of pollutant removal and disinfection in practical water treatment scenarios. This work provides a new solution to realize direct saline water electrolysis technology, promoting the development of this technology toward efficient, stable, and low-energy-consumption practical applications.