Coordinatively Unsaturated IrC ₃ Single‐Atom Catalysts for Efficient Methanol Oxidation Reaction

Abstract

ABSTRACT Methanol oxidation reaction (MOR) plays a crucial role in renewable energy conversion and storage, where the key steps involve dehydrogenation and subsequent * CO electrooxidation. However, * CO oxidation remains challenging due to its strong adsorption and insufficient * OH species at active sites, severely limiting reaction kinetics. Here, the single Ir atom catalyst with abundant coordinatively unsaturated IrC 3 sites is developed to electrocatalysis MOR under elevated temperature, the IrC 3 sites with stronger CH 3 OH adsorption and weaker * CO adsorption, which break the scaling relationship between methanol and * CO adsorption energy. Moreover, the IrC 3 could accelerate the electrochemical water dissociation with assistance of protophilic IrC 4 to form adsorbed * OH. The balanced adsorption energy and the appearance of ample * OH would efficiently decrease the reaction energy barriers, and further accelerate the methanol dehydrogenation and * CO oxidation. By assemble the high temperature polymer electrolyte membrane electrolyzer (HT‐PEME) with IrC 3 sites at 180°C, it shows an excellent MOR efficiency with onset potential about 0.05 V and H 2 generation rate with 8694 mol H2  mol Ir −1  h −1 at cathode, which is much higher than that of Ir‐C SACs parent catalyst and Pt/C catalysts. This finding provides an avenue to conquer the formidably sluggish kinetics of MOR for hydrogen utilization.