Mixed Metal Oxide Electrodes and the Chlorine Evolution Reaction

The chlorine evolution reaction (CER) has practical applications in the chlor-alkali industry and electrochemical wastewater treatment. Efficient, stable, and cost-effective electrodes are critical for energy efficient chlorine production, water disinfection, and wastewater treatment. These practical applications require an in-depth understanding of the catalytic mechanism of chlorine evolution, the need for lower-cost electrode materials, and improvements in electrode design at the atomic scale. Herein, we examine factors controlling activity, selectivity, and stability of alternative CER electrodes and provide mechanistic insights for achieving improvements in performance and durability. Steric effects of crystal structure and intermetallic electron polarization provide insights for understanding and tuning the electrode activity and selectivity. Additional insight into electrode deactivation mechanisms was gained by employing model material systems under controlled conditions. Herein, we explore viable strategies for the development of more efficient noble-metal-free CER electrodes for use in a variety of practical applications.