Electrosynthesis of chlorine from seawater-like solution through single-atom catalysts

The chlor-alkali process plays an essential role in modern chemical industry due to the wide-ranging applications of chlorine gas, but current chlorine evolution reaction (CER) electrocatalysts suffer from large overpotential and low selectivity. The authors report an oxygen-coordinated ruthenium single-atom catalyst (Ru-O4 SAM) for electrosynthesis of chlorine in seawater-like solutions. Ru-O4 SAM achieves an overpotential of only −30 mV at 10 mA cm−2 in 1 M NaCl (pH = 1). In a flow cell, the Ru-O4 SAM anode exhibits excellent stability and Cl2 selectivity over 1000 h at 1000 mA cm−2. Operando characterizations and computations reveal that, compared with RuO2, chloride ions preferentially adsorb directly onto Ru sites on Ru-O4 SAM, lowering the Gibbs free-energy barrier and improving Cl2 selectivity. This work provides mechanistic insight and a promising avenue for electrochemical chlorine synthesis from seawater-like electrolytes.

Yangyang Liu, Can Li, Chunhui Tan, Zengxia Pei, Tao Yang, Shuzhen Zhang, Qianwei Huang, Yihan Wang, Zheng Zhou, Xiaozhou Liao, Juncai Dong, Hao Tan, Wensheng Yan, Huajie Yin, Zhao-Qing Liu, Jun Huang, Shenlong Zhao