(100) Preferentially Exposed Pt-Sn Nanosheets with Enhanced C-C Bond Scission as a High-Performance Catalyst for Ethanol Oxidation

Ethanol is a kind of green and sustainableliquid fuel with highenergy density, which has a promising application prospect in liquidfuel cells. Improving the anti-poisoning ability and C-C bondcleavage ability of Pt-based catalysts is critical for achieving efficientethanol oxidation reaction. Here, Pt-Sn nanosheets preferentiallyexposed with metastable (100) facets rather than thermodynamicallystable (111) facets were synthesized through a simple hydrothermalmethod. Our experiment results demonstrated that the as-synthesized(100) faceted Pt-Sn nanosheets exhibited a good electrocatalyticperformance, i.e., higher CO2 selectivity and better stabilitywhen compared with Pt-Sn nanoparticles with irregular morphologyand commercial Pt/C. The electrochemical in situ infraredspectroscopy tests revealed that the Pt-Sn nanosheets alleviatethe binding strength of reaction intermediates and further promotethe electrooxidation of intermediates, thereby displaying a good CO2 selectivity at a lower potential and over a wide range ofpotentials. This work demonstrates the important roles of the faceteffect and alloying effect in electrocatalytic properties of noblemetal catalysts.