High-Performance Alcohol Electrooxidation on Pt3Sn-SnO2 Nanocatalysts through Transformation of Pt-Sn Nanoparticles
In this work, Pt3Sn-SnO2 supported on N-doped graphene (Pt3Sn-SnO2/NG) was synthesized by in situ transformation of Pt-Sn/NG by annealing at air atmosphere. The Pt3Sn-SnO2/NG catalyst characterized by XRD, TEM and HRTEM show the formation of ordered Pt3Sn intermetallic and every Pt3Sn NPs is closely contacted with one or more SnO2 NPs. The Pt3Sn-SnO2/NG catalyst shows outstanding performance towards ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR). The mass activity for EOR on Pt3Sn-SnO2/NG catalyst is 456 mA mg-1Pt at 0.7 V, more than 10 times than that of the commercial Pt/C catalyst (44 mA mg-1Pt). Pt3Sn-SnO2/NG catalyst is found to have 3 times more stable than commercial Pt/C. Our Pt3Sn-SnO2/NG catalyst also indicates enhanced MOR activity and high stability compared with the commercial Pt/C catalyst. In addition, Pt3Sn-SnO2/NG catalyst is also observed to have higher CO tolerance than the commercial Pt/C. The high activity and stability of Pt3Sn-SnO2/NG catalysts is attributed to the unique structure of Pt3Sn-SnO2 by in situ transformation of Pt-Sn/NG, which induce the formation of small size of ordered Pt3Sn intermetallic strongly interacted with contacted SnO2. The synergetic effect between ordered Pt3Sn and SnO2 not only enhances the activity towards EOR and MOR through the Sn in both Pt3Sn and SnO2 facilitate the oxidative removal of COads on the active sites of adjacent Pt at low potentials by providing OHads species, but also improves the stability by the strong Pt3Sn-SnO2 interaction.
- This article is part of the themed collection: 2019 Journal of Materials Chemistry A HOT Papers