Continuous Surface Strain Regulation in Trimetallic PtPbRu/Pt Nanoplates for Promoted Formic Acid Oxidation Catalysis

Regulating surface strain of platinum (Pt)-based nanomaterials to achieve efficient formic acid oxidation reaction (FAOR) catalysis for direct formic acid fuel cell (DFAFC) is crucial yet challenging. Herein, we adopt a continuous surface tensile strain modulation strategy to realize the superior activity, excellent stability, strong CO resistance, and high direct pathway selectivity for DFAFC. Atomic-level analysis reveals that controlling the partial substitution of Pb with Ru atoms modulates the lattice constant of the intermetallic core, thereby enabling precise control of biaxial strain in the Pt shell. The optimized 2.4%-PtPbRu/Pt nanoplates/C exhibits a mass activity of 10.0 A mg_Pt+Ru ^-1 for FAOR, 100.0 times higher than that of commercial Pt/C. Furthermore, its membrane electrode assembly achieves a high power density of 465.4 W g_Pt+Ru ^-1, 3.2 times greater than that of commercial Pt/C, along with an unprecedented lifetime at 0.4 V for 469.1 h with only 7.4% power density decay, representing the best FAOR catalysts reported to date. The introduced Ru increases tensile strain and downshifts Pt-5d orbitals, enhancing d-d orbital coupling, weakening CO^* adsorption, and promoting the HCOO^* adsorption to facilitate the direct formate pathway. It breaks through the strain-performance relationship bottleneck of traditional Pt-based catalysts, providing an atomic-scale design blueprint of efficient anodic catalysts for DFAFC.