Ultrafine Pt nanocrystals with an average particle size of 2.2 ± 1 nm coupled over the petaloid Fe2P surface are proposed as a novel, efficient, and robust catalyst for alcohol fuel electro-oxidation. The strong coupling effect of metal-support imparts a strong electronic interaction between the Fe2P and Pt interface that can weaken the adsorption of poisoning CO species according to the d-band theory. Defects and increased surface area of the petaloid Fe2P are beneficial to the Pt nanoparticle anchoring and dispersion as well as the charge transfer and reactant transportation during the electrochemical reaction. These features make the Pt-Fe2P catalyst system exhibit excellent catalytic activity, antipoisoning ability, and catalytic stability for alcohol fuel of methanol and ethanol electro-oxidation compared with a controlled Pt/C catalyst. The high catalytic efficiency is proposed to come from the strong coupling effect of Pt and petaloid Fe2P interface that can maintain the mechanical and chemical stability of the catalyst system. This kind of phosphide-supported ultrafine Pt nanocrystals will be a promising catalyst in fuel cells.
Keywords: alcohol fuel oxidation; electrocatalyst; fuel cells; iron phosphide; platinum nanocrystals.