Room‐Temperature Atomic Weaving of an Anisotropic Pd Single‐Atom‐Layer Catalyst With Orthogonal Strain for Formic Acid Oxidation

ABSTRACT Overcoming the fundamental trade‐off between high activation barriers and rapid desorption kinetics remains a central challenge in electrocatalyst design. Here we show that room‐temperature atomic weaving of anisotropic, freestanding, single‐atom‐thick Pd layers creates a bending‐poisson effect that establishes an orthogonal compressive‐tensile self‐strain network. Tensile‐strain‐induced lattice expansion accelerates spontaneous HCOOH dissociation, leading to dual‐CO adsorption on each Pd atom, while coordinated compressive–tensile domains facilitate product release by freeing bridge sites. In‐depth investigations reveal that compressive strain highly activates valence band with superior electron donation capability, while tensile strain generates accessible orbitals that suppress electronic coupling, collectively yielding a triply split electronic band structure. Consequently, the catalyst achieves a record CO adsorption capacity of 865 m 2 g −1 (372% above theoretical limits), 49.1‐fold formic acid oxidation activity enhancement over Pd/C, 618 mW cm −2 peak fuel cell power density. Moreover, the inherent structural flexibility confers high stability, retaining 89.4% of its initial activity after 440 h of accelerated degradation.