Self-Etching Pd–Pb Nanoparticles with Controllable Tensile Strain for C₂ Alcohol Oxidation

Pd-based nanocatalysts hold significant promise for application in alkaline direct ethanol fuel cells (DEFCs). To address the challenges of low Pd atom utilization and poor reaction kinetics in conventional Pd-based catalysts, a self-etching strategy has been developed to synthesize Pd₃Pb₁ nanoparticles (NPs) with tunable size and abundant tensile strain. The nanoparticles demonstrated a markedly enhanced electrocatalytic performance. Pd₃Pb₁ NPs-1 exhibited a current density of 2565 mA mg_Pd^-1 for the ethanol oxidation reaction (EOR). Following self-etching, smaller Pd₃Pb₁ NPs-2 were synthesized, achieving a higher current density of 2820 mA mg_Pd^-1 for EOR. Even after prolonged cyclic voltammetry (CV) testing, the Pd₃Pb₁ NPs-2 exhibited excellent stability. The high mass activity is attributed to a favorable balance between active intermediates and blocking species at the catalyst interface. This work presents a promising strategy for constructing nanocatalysts with tunable alloying degrees, offering highly efficient catalysts for fuel cell applications. Moreover, this study provides a reliable approach to preparing monodisperse nanocatalysts with controllable size and morphology through self-etching techniques.