Facile synthesis of trimetallic PtAuCu alloy nanowires as High−Performance electrocatalysts for methanol oxidation reaction

Abstract

The high cost, easy to be poisoned and poor stability of platinum (Pt) catalysts have limited their further application in various fields. The ability to impart Pt−based catalysts with high catalytic activity and low cost is critical to advancing fuel cell technologies. A promising strategy is applied to design Pt−based bimetallic or trimetallic nanostructures. The method of increasing electrocatalytic activity performance has attracted considerable attention by introducing other metal atoms for their unique structures and compositions. In this study, we report a solvothermal synthesis of trimetallic Pt−based (PtAuCu) alloy nanowires with controlled percentages of individual metals. By optimizing the content of Pt, Au and Cu, the trimetallic PtAuCu NWs nanowires show superior electrocatalytic activity toward methanol oxidation reaction (MOR). This enhanced electrocatalytic activity is due to the synergistic interactions of different metals. In particular, the incorporation of Cu can effectively reduce the use of precious metal Pt. And during the MOR process, the dissolution of Cu atoms from the PtAuCu surface, which can be attributed to a dealloying process, providing more Pt active sites for MOR thus enhancing the electrochemical activity. The electrochemical active surface area (ECSA) and mass activity of the Pt50Au10Cu40 alloy catalyst is approximately 1.5 and 4.34 times of commercial Pt/C catalyst, respectively. Moreover, it exhibits superior stability after 10000 s compared with the other catalysts. Thus, the multi−metal doping in Pt catalyst not only decreases the cost of Pt, but also exhibits a significant electrocatalytic performance, which is prospective for direct alcohol fuel cells.