SnO2 patched ultrathin PtRh nanowires as efficient catalysts for ethanol electrooxidation

Abstract

The limited electrochemical activities of Pt-based catalysts lead to the sluggish kinetics of the ethanol oxidation reaction (EOR). The delicate combination between SnO₂ and Pt-based nanocatalysts could effectively resolve this problem. Herein, SnO₂ patched ultrathin PtRh nanowires (PtRh@SnO₂ NWs) are synthesized by depositing and oxidizing Sn atoms on the surface of pre-formed PtRh NWs. Based on this method, SnO₂ patched ultrathin Pt, PtNi and PtRu NWs are produced as well by using different NW templates. Benefiting from the close proximity between Pt, Rh and amorphous SnO₂ patches, the oxidation of intermediates is enhanced, which is critical to boost the EOR electrocatalysis. Electrochemical measurements show that, compared with the other SnO₂ patched ultrathin Pt-based NWs, ultrathin PtRh@SnO₂ NWs with 40.7 at% SnO₂ exhibit the greatest mass activity of 3.16 A mg⁻¹ and specific activity of 5.63 mA cm⁻² towards the EOR in alkaline electrolyte, which are 5.3 and 4.3 times higher than those of commercial Pt/C, respectively. This work highlights the role of the structure and composition of ultrathin PtRh@SnO₂ NWs in boosting EOR electrocatalysis, and offers new insights into the design of advanced catalysts for broad application.