IrW nanochannel support enabling ultrastable electrocatalytic oxygen evolution at 2 A cm−2 in acidic media

A grand challenge for proton exchange membrane electrolyzers is the rational design of oxygen evolution reaction electrocatalysts to balance activity and stability. Here, we report a support-stabilized catalyst, the activated ~200 nm-depth IrW nanochannel that achieves the current density of 2 A cm−2 at an overpotential of only ~497 mV and maintains ultrastable gas evolution at 100 mA cm−2 at least 800 h with a negligible degradation rate of ~4 μV h−1. Structure analyses combined with theoretical calculations indicate that the IrW support alters the charge distribution of surface (IrO2)n clusters and effectively confines the cluster size within 4 (n≤4). Such support-stabilizing effect prevents the surface Ir from agglomeration and retains a thin layer of electrocatalytically active IrO2 clusters on surface, realizing a win-win strategy for ultrahigh OER activity and stability. This work would open up an opportunity for engineering suitable catalysts for robust proton exchange membrane-based electrolyzers. Although electrocatalytic water splitting can generating renewable fuels, it is challenging to find water oxidation catalysts that are stable in acid at high current densities. Here, authors explore IrW as oxygen evolution electrocatalysts maintaining high current densities for hundreds of hours.