Sheng Ma, Xinze Li, Taoda Liu, Ke Yuan, Mengjun Tang, Waqas Muhammad, Xiaoling He, Tian Ouyang, Xi Zhang, Tao Wenyan, Yinghua Niu, Zhen Zhang, Weiqiang Lv
ABSTRACT The development of low‐cost and high‐performance noble‐metal‐free catalysts for the oxygen evolution reaction (OER) is central to advancing alkaline water electrolysis. This work introduces a novel “composition–thermal history” design strategy, synergistically combining controlled A‐site Sr 2+ doping with optimized high‐temperature sintering (950°C) in Pr‐based perovskite. The resulting Pr 0.75 Sr 0.25 Ni 0.7 Co 0.3 O 3 (PSNC‐25) exhibits unprecedented nanostructuring and a maximized concentration of oxygen vacancies, unlocking efficient OER via lattice oxygen‐mediated mechanism. Sr‐induced lattice distortion drastically reduces oxygen vacancy formation energy from 2.06 to 1.14 eV, promoting facile lattice oxygen participation. Thermal engineering stabilizes high‐valence Co 4+ /Ni 3+ states and enhances M─O covalency. Electrochemically, PSNC‐25 achieves exceptional activity in 1 M KOH: a low overpotential of 389 mV at 10 mA cm −2 and a Tafel slope of 83 mV dec −1 , significantly surpassing undoped PrNi 0.7 Co 0.3 O 3 (η 10 ＞ 570 mV). It also exhibits robust durability, by > 120 h chronopotentiometry at 10 mA cm −2 with only ∼45 mV potential drift. This work establishes a rational framework for activating LOM in cost‐effective perovskites through dopant‐induced electronic modulation and nano‐structural control, advancing scalable green hydrogen production.