Experimental and density functional theory studies on PtPb/C bimetallic electrocatalysts for methanol electrooxidation reaction in alkaline media

Carbon-supported bimetallic PtmPb1 (m = 1, 2, 3) electrocatalysts with different Pt/Pb atomic ratios were synthesized by a polyol method. The X-ray diffraction results reveal that a PtPb alloy formed in the PtmPb1/C electrocatalysts. TEM images show that the PtPb nanoparticles distribute uniformly on the carbon support, and are about 4–5 nm in size. The PtmPb1/C bimetallic catalysts show superior activities toward methanol electrooxidation reaction (MOR) than the Pt/C in alkaline media. Both CO stripping measurements and density functional theory studies reveal that CO adsorption decreased significantly on the PtmPb1/C bimetallic catalysts compared with on pure Pt, which may offer an explanation for the enhanced MOR activity of the PtmPb1/C bimetallic catalysts.

► The addition of Pb modifies the electronic structure of Pt. ► The addition of Pb inhibits the CO adsorption on Pt due to the geometric hindrance. ► The Eads for bridge/hollow site adsorbed PtmPbn-CO is greatly decreased. ► The PtmPb1/C catalysts show decreased MOR onset potential and enhanced MOR activity.