<p>The lack of mechanistic understanding and catalyst design principles for alkaline electrolytes, especially for the sluggish oxygen reduction reaction, has impeded the advancement of alkaline fuel cells. Here we propose a modified volcano plot and apply this rationale to strategically design Pt nanosheets with PdH_<i>x</i> nanosheets substrates. This catalyst exhibited high stability with a specific activity of 1.71 mA cm⁻² at 0.95 V versus the reversible hydrogen electrode, surpassing the benchmark of Pt/C by 49-fold. Spectroscopic, electrochemical and electron microscopic characterizations revealed that such performance enhancement originated from tensile-strained Pt{111} facets, improving oxidative stability and suppressing carbon corrosion. In fuel cell testing, the catalyst enabled a peak power density of 1.67 W cm⁻² with a loading of 10 µg_{PGM Cathode} cm⁻². Further optimization delivered a peak power density of 21.7 W mg⁻¹_{PGM Cathode+Anode} with a total specific catalyst cost US$1.27 kW⁻¹, surpassing the US Department of Energy’s Pt group metal loading and cost targets. This study provides valuable insights into catalyst design for the alkaline oxygen reduction reaction.</p>