Self-Etching Pd–Pb\nNanoparticles with Controllable\nTensile Strain for C<sub>2</sub> Alcohol Oxidation

Pd-based nanocatalysts hold significant promise for application\nin alkaline direct ethanol fuel cells (DEFCs). To address the challenges\nof low Pd atom utilization and poor reaction kinetics in conventional\nPd-based catalysts, a self-etching strategy has been developed to\nsynthesize Pd<sub>3</sub>Pb<sub>1</sub> nanoparticles (NPs) with tunable\nsize and abundant tensile strain. The nanoparticles demonstrated a\nmarkedly enhanced electrocatalytic performance. Pd<sub>3</sub>Pb<sub>1</sub> NPs-1 exhibited a current density of 2565 mA mg<sub>Pd</sub><sup>–1</sup> for the ethanol oxidation reaction (EOR).\nFollowing self-etching, smaller Pd<sub>3</sub>Pb<sub>1</sub> NPs-2\nwere synthesized, achieving a higher current density of 2820 mA mg<sub>Pd</sub><sup>–1</sup> for EOR. Even after prolonged cyclic\nvoltammetry (CV) testing, the Pd<sub>3</sub>Pb<sub>1</sub> NPs-2 exhibited\nexcellent stability. The high mass activity is attributed to a favorable\nbalance between active intermediates and blocking species at the catalyst\ninterface. This work presents a promising strategy for constructing\nnanocatalysts with tunable alloying degrees, offering highly efficient\ncatalysts for fuel cell applications. Moreover, this study provides\na reliable approach to preparing monodisperse nanocatalysts with controllable\nsize and morphology through self-etching techniques.