Durable Platinum Thin Film on Silver Leaf, Formed by Self‐Terminating Electrodeposition

The high cost and limited availability of platinum (Pt) remain major barriers to the widespread deployment of proton‐exchange membrane fuel cells (PEMFCs). Here, we report a novel and scalable strategy for fabricating ultradurable electrocatalysts with low Pt loading using commercially available silver (Ag) leaf (varakh) as a low‐cost substrate. A modified self‐terminating electrodeposition (STED) protocol was adapted to deposit Pt overlayers while suppressing galvanic displacement and substrate corrosion. A key feature of this approach is an in situ electrochemical activation step involving controlled potential cycling up to 1.25 V RHE . This process selectively leaches residual Ag and generates a stable, nanoporous, Pt‐enriched architecture accompanied by Ag–Pt alloy formation. The resulting catalyst exhibits a Pt loading of 52.1 ± 3.7 µg cm −2 and an initial electrochemically active surface area (ECSA) of 8.36 ± 0.07 m 2 g −1 . Remarkably, no ECSA degradation is observed over 30 000 potential durability cycles, meeting the US Department of Energy targets while maintaining cost‐effective Pt utilization for PEMFC applications.