Room-Temperature Atomic Weaving of an Anisotropic Pd Single-Atom-Layer Catalyst With Orthogonal Strain for Formic...

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 m² 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.