Lattice Strain and Surface Activity of Dislocation-Distorted AgPd Nanoalloys Under Preoxidation and Catalysis Condition

Although line defects endow excellent catalytic performance by undercoordinated sites with compressive tensile strain, few studies have systematically unraveled the relationship between dislocation, strain, and electrochemical activity for formate oxidation reactions (FOR). Herein, a novel approach for synthesizing defect-rich nanomaterials at room temperature is proposed for the first time. The heated and dealloyed AgPd nanoparticles (hd-AgPd NPs) substantially improve the intrinsic electrocatalytic activity by introducing compressive strain to tune its electronic structure. Electrochemical experiments show that the mass activity of hd-AgPd NPs for FOR is 5.3 times higher than that of pure Pd nanoparticle catalysts. Following a 3600 s chronoamperometric process, a portion of the dislocation vanishes, but the strain persists on the AgPd (111) facet. The mechanisms for activity enhancement are further explored through density functional theory and molecular dynamics calculations, which show that compressive strain effectively alters its electronic structure and decreases the energy of the rate-determining step during the reaction, significantly enhancing the FOR performance and stability. The results of electrochemical performance and physical characterization show that lattice strain has a more significant impact on FOR performance than alloying and preoxidation. This study presents a new approach to produce high-performance catalysts by inducing strain into nanoparticles.