Atomically dispersed hexavalent iridium oxide from MnO 2 reduction for oxygen evolution catalysis

作者：Ailong Li, Shuang Kong, Kiyohiro Adachi, Hideshi Ooka, Kazuna Fushimi, Qike Jiang, Hironori Ofuchi, Satoru Hamamoto, Masaki Oura, Kotaro Higashi, Takuma Kaneko, Tomoya Uruga, Naomi Kawamura, Daisuke Hashizume, Ryuhei Nakamura · 发表于：Science · 年份：2024 · DOI：10.1126/science.adg5193 · 被引用次数：446 · 研究领域：Electrocatalysts for Energy Conversion、Fuel Cells and Related Materials、Advanced Memory and Neural Computing

Hexavalent iridium (Ir VI ) oxide is predicted to be more active and stable than any other iridium oxide for the oxygen evolution reaction in acid; however, its experimental realization remains challenging. In this work, we report the synthesis, characterization, and application of atomically dispersed Ir VI oxide (Ir VI - ado ) for proton exchange membrane (PEM) water electrolysis. The Ir VI - ado was synthesized by oxidatively substituting the ligands of potassium hexachloroiridate(IV) (K 2 IrCl 6 ) with manganese oxide (MnO 2 ). The mass-specific activity (1.7 × 10 5 amperes per gram of iridium) and turnover number (1.5 × 10 8 ) exceeded those of benchmark iridium oxides, and in situ x-ray analysis during PEM operations manifested the durability of Ir VI at current densities up to 2.3 amperes per square centimeter. The high activity and stability of Ir VI - ado showcase its promise as an anode material for PEM electrolysis.