Porous and B‐site Substituted Y₂[Mn_0.2Ru_0.8]₂O₇ Pyrochlore for Boosting Acidic Water Oxidation Activity and Stability

Abstract Boosting the reaction stability without sacrificing the activity and cost is extremely important but full of challenges for the RuO 2 ‐based oxygen evolution catalysts. Herein, porous and B‐site substituted Y 2 [Mn 0.2 Ru 0.8 ] 2 O 7 (p‐Y 2 [Mn 0.2 Ru 0.8 ] 2 O 7 ) pyrochlore toward oxygen evolution reaction is innovatively synthesized. The formed meso‐/macroporous structure can increase the specific surface area and corresponding active sites, meanwhile, Mn‐substitution can modulate the electronic structure, stabilize the morphology, and reduce the dosage of Ru species. Interestingly, the p‐Y 2 [Mn 0.2 Ru 0.8 ] 2 O 7 performs 50 h stable operation, significantly outperforming the commercial RuO 2 (CM) counterpart with less than 2 h life. Furthermore, the required overpotential to achieve 10 mA cm −2 is only 266 mV, accompanied with favorable reaction kinetics and catalyst utilization.