Iridium Dioxide Nanoparticles and Zinc Single Atoms Co-Anchored to Porous Carbon Nanofibers for Excellent Chlorine...

Iridium dioxide (IrO₂) is extensively used in the chlor-alkali industry as a catalyst for the chlorine evolution reaction (CER) and is a key component of dimensionally stable anodes (DSAs). However, its performance deteriorates in acidic media owing to its structural instability and mass transfer limitations at high current densities. To boost the CER activity, the electrical conductivity and corrosion resistance of IrO₂-based electrodes are improved by optimizing the electronic structure and distributing the surface-active sites. In this study, we synthesized a structure comprising porous carbon nanofibers (CNFs) to which IrO₂ nanoparticles and zinc single atoms were anchored (IrO₂@Zn-N₄-PCNFs). The optimized catalyst has a low overpotential (96 mV, 10 mA cm^-2) and retains 99% of its initial current over 24 h, thereby outperforming the commercial DSA (119 mV, 95%). This enhanced performance is attributed to the abundant CER-active sites formed by the synergistic interaction between IrO₂ nanoparticles and Zn-N₄ sites. Additionally, the hierarchical porous structure and conductive CNFs provide a large surface area (384.58 m² g^-1) and allow efficient mass transport. This paper presents a promising strategy for designing durable high-performance CER catalysts and contributes to the development of next-generation anode materials for chlor-alkali electrolysis.