Stability of dimensionally stable anode for chlorine evolution reaction

Chlorine (Cl-2) is one of the most important chemicals produced by the electrolysis of brine solutions and is a key raw material for many areas of industrial chemistry. For nearly half a century, dimensionally stable anode (DSA) made from a mixture of RuO2 and TiO2 solid oxides coated on Ti substrate has been the most widely used electrode for chlorine evolution reaction (CER). In harsh operating environments, the stability of DSAs remains a major challenge greatly affecting their lifetime. The deactivation of DSAs significantly increases the cost of the chlor-alkali industry due to the corrosion of Ru and the formation of the passivation layer TiO2. Therefore, it is urgent to develop catalysts with higher activity and stability, which requires a thorough understanding of the deactivation mechanism of DSA catalysts. This paper reviews existing references on the deactivation mechanisms of DSA catalysts, including both experimental and theoretical studies. Studies on how CER selectivity affects electrode stability are also discussed. Furthermore, studies on the effects of the preparation process, elemental composition, and surface/interface structures on the DSA stability and corresponding improvement strategies are summarized. The development of other non-DSA-type catalysts with comparable stability is also reviewed, and future opportunities in this exciting field are also outlined.