Chlorine, a key industrial chemical, is primarily produced through the chlor-alkali process using mixed-metal oxides (MMOs) like dimensionally stable anode (DSA). These anodes face challenges of high overpotential and poor selectivity due to competing oxygen evolution reaction (OER) pathways. This work presents a Zn-doped, defect-engineered RuTiSnZnOx catalyst on Ti foam to address these issues. The introduction of low-valence Zn creates lattice defects and induces a charge-deficient state at Ru sites. Critically, in-situ electrochemical Raman spectroscopy revealed that this Zn doping facilitates a decisive shift in the key reaction intermediate from Ru-O-Cl to Ru-Cl. This change in the intermediate species directly suppresses the competing OER pathway, thereby enhancing chlorine evolution reaction (CER) selectivity. The catalyst achieves a remarkably low overpotential of 45 mV at 10 mA·cm–2 and exhibits excellent stability with only 13 mV decay after 1000 hours of operation at 100 mA·cm–2. Density functional theory (DFT) calculations further demonstrate that Zn incorporation optimizes the electronic structure by shifting the Ru d-band center closer to the Fermi level. This study elucidates how defect engineering through doping can selectively modulate reaction intermediates, providing a new strategy for developing high-performance, cost-effective CER electrocatalysts.
Peng et al. (Wed,) studied this question.