Structurally Robust Honeycomb Layered Strontium Iridate as an Oxygen Evolution Electrocatalyst in Acid

The poor catalyst stability, stemming from serious cationdissolutionand uncontrollable amorphization, remains an outstanding problem inthe acidic oxygen evolution reaction (OER). Herein, we report thesynthesis and characterization of honeycomb layered strontium iridate(SrIr2O6) and demonstrate its potential as anefficient OER electrocatalyst with robust structural stability inacid. In contrast to the vast majority of iridate catalysts, SrIr2O6 can keep both bulk and surface structures crystallineduring OER, as opposed to forming an amorphous active phase. The edgesof SrIr2O6 are highly catalytically active forOER by following the adsorbate evolution mechanism, but the basalplanes are catalytically inert. SrIr2O6 exhibits similar to 10-fold higher intrinsic activity than the benchmark catalystIrO(2), affords an extremely low total iridium leaching level(similar to 0.03%) during OER, and retains its catalytic activity formore than 300 h.