Ti/RuO2-IrO2-SnO2-Sb2O5 Anodes for Cl2 Evolution from Seawater

Abstract

Seawater can be used as an electrolyte for Cl 2 evolution, and proper selection of electrode materials is of great importance. In this paper, a new type of dimensionally stable anodes, Ti/RuO 2 -IrO 2 -Sb 2 O 5 -SnO 2 , was investigated for Cl 2 evolution from seawater. The physicochemical and electrochemical properties were examined, and the electrocatalytic activity for Cl 2 evolution was measured under different conditions. It was shown that the RuO 2 -IrO 2 -Sb 2 O 5 -SnO 2 coating was compact in microstructure. The current efficiency was 71.2-86.7%, depending on the operational conditions. The anodes were predicted to be able to work effectively for over 6 years at a current density of 1500 A m −2 for seawater electrolysis.

Recent advances in electrocatalytic chloride oxidation for chlorine gas production

“…Subsequently, the RuO 2 -IrO 2 -Sb 2 O 5 -SnO 2 electrode was prepared using a similar method. 12 The asobtained quaternary MMOs exhibit a lower onset potential that is about 50 mV less than that of ternary MMOs. Meanwhile, the quaternary MMOs have a faradaic efficiency at around 86.7% in seawater electrolysis.…”

“…58,59 At the same time, the SnO 2 -Sb 2 O 5 mixture has been shown to provide a good platform for producing chlorine from seawater electrocatalysis. 11,12 Theoretically, the Sb 5+ can be well incorporated with Sn 4+ due to a similar ionic radius. Also, SnO 2 conductivity will be optimized by interactions among the different components that optimize the catalytic properties.…”

“…Sn, Sb) doped into RuO 2 were synthesized as CER electrocatalysts with a low overpotential and excellent faradaic efficiency (FE). [11][12][13][14] Besides, the latest research indicated that size tailoring could be an efficient approach to improve the utilization and accessibility of active sites, leading to greatly improved performance in low Cl À concentration electrolytes. 15 Apart from noble metal-based catalysts, earthabundant transition metal oxides such as Co 3 O 4 and CoSb 2 O x have been reported to provide abundant active sites and extraordinary durability for effective electrocatalytic chlorine evolution.…”

Microwave synthesis of Ti/(RuO2)0.5(IrO2)0.5 anodes: Improved electrochemical properties and stability

“…The use of CO2 laser (as well as the use of microwave, the method used in this work), produced anodes with surfaces that are more compact and with longer lifetime (1.6 times), compared to the conventional Pechini method. Additionally, by using the equation proposed by Wang et al [29], we can estimate the service lifetime. For the 350ºC microwave-synthesized electrode, the lifetime is about 15 years.…”

“…Accelerated service life tests were performed in 1.0 mol L -1 H2SO4 solution with an applied current density of 1.0 A cm -2 . The anodes were considered deactivated when the measured potential reached 10 V. Wang et al [29] have developed a relationship between anode service life (𝑆 𝐿 ) and current density (i) can be represented by Eq. 1.…”