摘要：The large‐scale application of proton exchange membrane water electrolysis technology requires the development of high‐performance oxygen evolution electrocatalysts with as little iridium(Ir)as ***‐based double perovskite oxides(A_(2)B’IrO_(6);A=alkaline,alkaline‐earth,or rare‐earth elements;B’=transition metal or rare‐earth elements)represent a class of oxides with great potential to replace the commercial catalyst IrO_(2).However,the structural evolution of Ir‐based double perovskite oxides in electrolytes is incompletely understood,and foundational knowledge of the design principle of the“ideal”material is *** this work,we report the unexpected phenomenon of instant Ir leaching from Ir‐based double perovskite oxides in acid under non‐catalytic conditions and discuss the implications of this phenomenon for mechanism investigation and material *** well‐known Ir‐based double perovskite oxides,such as Ba_(2)PrIrO_(6) and Sr_(2)YIrO_(6),undergo instantaneous Ir leaching when they come into contact with acidic *** Ir‐leaching process is found to be non‐persistent and non‐thermodynamically determined,and its extent is correlated with the leaching of other B’‐site elements in the perovskite *** on this observation,we revisit the Ir dissolution‐precipitation process for surface IrO_(x) formation during the perovskite‐electrolyzed oxygen evolution reaction,emphasizing the non‐negligible role of Ir species owing to acid corrosion in the ***,we modify a screening protocol for low‐Ir oxygen evolution electrocatalysts and propose an instant acid corrosion test as an indispensable process to evaluate the structural stability of potential catalysts.