Pt3Sn nanoparticles enriched with SnO2/Pt3Sn interfaces for highly efficient alcohol electrooxidation.

Abstract

Pt3Sn nanoparticles (NPs) enriched with Pt3Sn/ultra-small SnO2 interfaces (Pt3Sn@u-SnO2/NG) were synthesized through a thermal treatment of Pt2Sn/NG in a H2 atmosphere, followed by annealing under H2 and air conditions. The unique structure of Pt3Sn NPs enriched with Pt3Sn/SnO2 interfaces was observed on the Pt3Sn@u-SnO2/NG catalyst based on HRTEM. The optimized Pt3Sn@u-SnO2/NG catalyst achieves high catalytic activity with an ethanol oxidation reaction (EOR) activity of 366 mA mgPt−1 and a methanol oxidation reaction (MOR) activity of 503 mA mgPt−1 at the potential of 0.7 V, which are eight-fold and five-fold higher than those for the commercial Pt/C catalyst (44 and 99 mA mgPt−1, respectively). The Pt3Sn@u-SnO2/NG catalyst is found to be 3 times more stable and have higher CO tolerance than Pt/C. The outstanding performance of the Pt3Sn@u-SnO2/NG catalyst should be ascribed to the synergetic effect induced by the unique structure of Pt3Sn NPs enriched with Pt3Sn/SnO2 interfaces. The synergetic effect between Pt3Sn NPs and ultra-small SnO2 increases the performance for alcohol oxidation because the Sn in both Pt3Sn and SnO2 favors the removal of COads on the nearby Pt by providing OHads species at low potentials. The present work suggests that the Pt3Sn@u-SnO2 is indeed a unique kind of efficient electrocatalyst for alcohol electrooxidation.