Assembly of Ultrathin Palladium‐Platinum Nanosheets for Efficient C1 and C2 Alcohol Oxidation

Abstract Direct alcohol fuel cells (DAFCs) are promising energy conversion technologies due to their low toxicity, high energy density, and versatile fuel sources. However, the lack of efficient and stable anode catalysts remains a critical obstacle to commercialization. Herein, we report a class of palladium‐platinum nanosheet assemblies (Pd‐Pt NSAs) with tunable compositions (Pd₇Pt₃, Pd₄Pt₁, and Pd₉Pt₁) and a face‐centered cubic structure, designed to boost methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) performance. These catalysts feature a unique multilayered nanosheet structure, which provides abundant active sites and high electrochemically active surface areas (ECSAs). Among the synthesized catalysts, Pd₄Pt₁ NSA demonstrates exceptional mass activities of 2310 mA mg⁻¹ for MOR and 2260 mA mg⁻¹ for EOR, surpassing commercial Pd/C by 7.62‐fold and 4.09‐fold, respectively. The superior performance arises from three synergistic factors: (i) Electronic modulation via ligand effects (electron transfer between Pd and Pt) and strain effects (lattice expansion with minimal Pd‐Pt lattice mismatch ≤ 0.77%), which collectively optimize intermediate adsorption; (ii) Enhanced ECSAs enabled by the ultrathin, high‐surface‐area nanosheet assemblies; (iii) Structural robustness of the interconnected nanosheet network, ensuring long‐term stability. This work provides a scalable strategy for engineering Pd/Pt‐based nanostructures with atomic‐level control, offering new avenues for high‐performance fuel cell catalysts.