SnO2 patched ultrathin PtRh nanowires as efficient catalysts for ethanol electrooxidation

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.