Rational Design of Dimensionally Stable Anodes for Active Chlorine Generation
Hyun Woo Lim, Deok Ki Cho, Jae Hyun Park, Ji Su, You Jin Ahn, Jin Young Kim, Chan Woo Lee
Abstract
RuO2 is one of the most important electrocatalyst materials as a key component of dimensionally stable anode (DSA) for chlorine evolution reaction, because of the high catalytic activity, while anodic corrosion remains a fundamental challenge that must be addressed. Here, we demonstrate that low-temperature annealing of RuO2 nanoparticles (∼1.7 nm) supported on Nb-doped TiO2 leads to the formation of durable active sites with superior activity and product selectivity toward active chlorine generation (10 mA cm–2 at 22 mV overpotential with a Faradaic efficiency of 97.3% in 0.6 M NaCl, which is much better than that of commercial DSA). The Nb doping not only enhances the electronic conductivity of TiO2 support, but also enables thermal diffusion of Ti atoms into the RuO2 lattice at only 200 °C, forming ultrafine solid-solution nanoparticles with ultrathin TiO2 surface as a protective layer. This work provides a cost-effective fabrication strategy of stable RuO2 electrocatalysts for anodic reactions, as well as additional insights into the design principle of DSA.