Diluted silicon promoting Pd/Pt catalysts for oxygen reduction reaction with strong anti-poisoning effect

Poisoning species, such as methanol and air pollutants, degrade the electrocatalytic activity for oxygen reduction reaction (ORR). Here, via taking advantage of the varied electronic property of nano-silicon, a versatile strategy is reported for enhancing the catalytic activity and anti-poisoning ability toward ORR by decorating noble metal catalysts with the size-controlled silicon nanoclusters (DS). Consequently, DS-Pd exhibits the enhanced ORR performance with a large halfwave potential of 0.892 V and an onset potential of 1.010 V. More importantly, it also shows enhanced anti-poisoning performance in methanol, NaNO 2 and NaHSO 3 electrolytes, compared to those of commercial Pt/C and Pd/C catalysts. Mechanism studies reveal that the synergistic effect between Pd and more oxygen-philic and less poison-philic Si nanoclusters largely abbreviate the absorption of poisoning species on the active sites. This strategy also improves the methanol-tolerant performance of Pt based catalysts, providing a versatile strategy for the fabrication of methanol-tolerant ORR catalysts. The diluted silicon nanoclusters enhance the catalytic activity and anti-poisoning ability of noble metal (Pd or Pt) catalysts toward oxygen reduction reaction (ORR). DS-Pd exhibits the improved ORR performance with a large halfwave potential of 0.892 V and an onset potential of 1.010 V. The remarkable anti-poisoning performance is due to the strong interaction between Si nanoclusters and Pd that weakens the adsorption poisons on Pd as confirmed by Raman spectra and DFT calculation. • Diluted silicon nanoclusters reduce the d band center of Pd atoms. • A lower d band center of Pd further weakens the adsorption of poisons. • Diluted silicon nanoclusters increase the catalytic activity of Pd or Pt toward ORR. • Diluted silicon nanoclusters enhance the anti-poisoning performance of Pd or Pt. • DS-Pd exhibits improved ORR performance with a halfwave potential of 0.892 V.