Increased interface effects of Pt[sbnd]Fe alloy/CeO2/C with Pt[sbnd]Fe selective loading on CeO2 for superior performance in direct methanol fuel cell

Abstract

Here, a simple two-step solvothermal approach has been employed to synthesize PtFe alloy (or Pt)/CeO2/C with PtFe (or Pt) selective loading on CeO2 nanoparticles. In addition, the selective loading of PtFe alloy or Pt nanoparticles on the surface of CeO2 is achieved under weak alkaline environment, which is mainly attributed to the opposite electrostatic force between H+ enriched on the surface of CeO2 particles and OH− covered with carbon supporters. As-prepared PtFe alloy (or Pt)/CeO2/C catalysts with two-stage loading structures show more excellent electro-catalytic efficiency for methanol oxidation as well as duration compared with commercial Pt/C and PtCeO2/C with random loading structure. Further, single-cell assembly based on Pt3Fe/CeO2/C as the anode catalyst exhibits a maximum power density of 31.1 mW cm−2, which is 1.95 times that of an analogous cell based on the commercial Pt/C. These improved performances with considerable low Pt content (<0.3 mg cm−2) are mainly ascribed to the abundant three phase interfaces (PtCeO2 carbon) induced by the selective and efficient dispersion of Pt nanoparticles on ceria.