An iron-base oxygen-evolution electrode for high-temperature electrolyzers
Kaifa Du, Enlai Gao, Chunbo Zhang, Yongsong Ma, Peilin Wang, Rui Yu, Wenmiao Li, Kaiyuan Zheng, Xinhua Cheng, Diyong Tang, Bowen Deng, Huayi Yin, Dihua Wang
Abstract
Abstract High-temperature molten-salt electrolyzers play a central role in metals, materials and chemicals production for their merit of favorable kinetics. However, a low-cost, long-lasting, and efficient high-temperature oxygen evolution reaction (HT-OER) electrode remains a big challenge. Here we report an iron-base electrode with an in situ formed lithium ferrite scale that provides enhanced stability and catalytic activity in both high-temperature molten carbonate and chloride salts. The finding is stemmed from a discovery of the ionic potential-stability relationship and a basicity modulation principle of oxide films in molten salt. Using the iron-base electrode, we build a kiloampere-scale molten carbonate electrolyzer to efficiently convert CO 2 to carbon and oxygen. More broadly, the design principles lay the foundations for exploring cheap, Earth-abundant, and long-lasting HT-OER electrodes for electrochemical devices with molten carbonate and chloride electrolytes.