Ultrathin iridium carbonyl formate for efficient and durable acidic oxygen evolution electrocatalysis

Abstract

Proton exchange membrane water electrolyzer (PEMWE) currently relies on the benchmarking iridium (Ir)-based electrocatalysts for acidic oxygen evolution reaction (OER) on the anode. Herein, we report a novel two-dimensional (2D) complex-based electrocatalyst of Ir carbonyl formate (IrCF) with atomic-level thickness architecture, synthesized by a fast microwave method, for highly active and stable OER in an acidic solution. The local atomic coordination configuration of Ir active sites can be further finely regulated by introduction of 1,3,5-benzenetricarboxylic molecules to enhance the OER performance. The optimized overpotential as low as 248 mV can be achieved at a current density of 10 mA cm-2 in 0.1 M HClO4 solution, with accelerated kinetics showing a Tafel slope of 32 mV dec-1. The 2D IrCF could work stably at the current density of 1 A cm-2 in a PEMWE device for more than 100 hours without obvious degradation.