TY - JOUR
T1 - Hexavalent Iridium Sites Drive Highly Efficient and Selective Chlorine Evolution via a Two-Step Chemical-Electrochemical Cycle Reaction Mechanism
AU - Chen, Siqi
AU - Ouyang, Bo
AU - Liu, Qichen
AU - Wang, Fangmu
AU - Zhang, An
AU - Yin, Shuai
AU - Cao, Rong
AU - Yan, Jiangcheng
AU - Chen, Gen
AU - Zheng, Xusheng
AU - Kan, Erjun
AU - Jiang, Wei
AU - Wang, Dingsheng
AU - Ye, Jinhua
AU - Liu, Guigao
PY - 2026/3/9
Y1 - 2026/3/9
N2 - Chlorine evolution reaction (CER) is pivotal to the chlor-alkali industry, while its operation still relies on the dimensionally stable anode (DSA) developed decades ago, which is hindered by high costs, moderate selectivity, and limited energy efficiency. Here, we present a spinel-type hexavalent iridium single-site electrocatalyst (spinel-iso-IrVI) via strategic modulation of delocalized electron distribution that demonstrates exceptional CER performance. This catalyst operates with an ultralow overpotential of 27 mV at 10 mA cm−2 (57 mV for commercial DSA), a nearly 100% CER selectivity across a wide potential range, and a record energy efficiency of 83.5% at an industrial-level current density of ∼300 mA cm−2. At the overpotential of 100 mV, spinel-iso-IrVI delivers a mass activity of 9671 mA mgRu+Ir−1 and a turnover frequency of 0.278 s−1, surpassing those of the benchmark DSA by over 386-fold and 20-fold, respectively. The high-performance of spinel-iso-IrVI results in a low production cost of US$0.04 per kilogram of chlorine. Mechanism studies reveal a two-step chemical-electrochemical cycle reaction mechanism, in which the chemical reaction step involves a spontaneous redox reaction triggered by hexavalent IrVI sites. This process enables the spontaneous adsorption, bonding, and oxidation of Cl− to generate Cl2, thereby significantly boosting the reaction kinetics.© 2026 Wiley-VCH GmbH
AB - Chlorine evolution reaction (CER) is pivotal to the chlor-alkali industry, while its operation still relies on the dimensionally stable anode (DSA) developed decades ago, which is hindered by high costs, moderate selectivity, and limited energy efficiency. Here, we present a spinel-type hexavalent iridium single-site electrocatalyst (spinel-iso-IrVI) via strategic modulation of delocalized electron distribution that demonstrates exceptional CER performance. This catalyst operates with an ultralow overpotential of 27 mV at 10 mA cm−2 (57 mV for commercial DSA), a nearly 100% CER selectivity across a wide potential range, and a record energy efficiency of 83.5% at an industrial-level current density of ∼300 mA cm−2. At the overpotential of 100 mV, spinel-iso-IrVI delivers a mass activity of 9671 mA mgRu+Ir−1 and a turnover frequency of 0.278 s−1, surpassing those of the benchmark DSA by over 386-fold and 20-fold, respectively. The high-performance of spinel-iso-IrVI results in a low production cost of US$0.04 per kilogram of chlorine. Mechanism studies reveal a two-step chemical-electrochemical cycle reaction mechanism, in which the chemical reaction step involves a spontaneous redox reaction triggered by hexavalent IrVI sites. This process enables the spontaneous adsorption, bonding, and oxidation of Cl− to generate Cl2, thereby significantly boosting the reaction kinetics.© 2026 Wiley-VCH GmbH
KW - chlorine evolution
KW - chemical-electrochemical cycle reaction mechanism
KW - electrochemistry
KW - heterogeneous catalysis
KW - hexavalent iridium sites
UR - https://www.webofscience.com/wos/woscc/full-record/WOS:001680378400001
U2 - 10.1002/anie.202524546
DO - 10.1002/anie.202524546
M3 - RGC 21 - Publication in refereed journal
SN - 1433-7851
VL - 65
JO - Angewandte Chemie International Edition
JF - Angewandte Chemie International Edition
IS - 11
M1 - e24546
ER -