Surface sites assembled-strategy on Pt-Ru nanowires for accelerated methanol oxidation

Modifying the surface active sites of Pt-based catalysts at the atomic level is of great significance to enhance the electrooxidation of methanol molecules. Herein, efficient active site assembly strategies are proposed, precisely, aimed at building high-performance electrocatalysts. Serving as proof-of-concept examples, both instances of Pt nanowires surface doping isolated Ru atoms (Ru/Pt NWs) and Ru nanoparticles supported on Pt nanowires (Ru@Pt NWs) are specially designed to optimize the catalytic performance of methanol oxidation reaction (MOR). The specific activity and mass activity of optimal Ru/Pt NWs can reach up to 3.93 mA cm-2 and 568.40 mA mg-1Pt, respectively, which is 1.53/1.94 times that of the Ru@Pt NWs and 2.03/2.59 times that of pure Pt NWs. Detailed studies on mechanism reveal that the Pt-Ru alloy can significantly improve the electron transfer kinetics of MOR, and activate more Pt atoms involved in the Langmuir-Hinshelwood (L-H) pathway compared with Ru@Pt NWs, all of which collectively accelerate the methanol oxidation. This surface engineering strategy via assembling active sites can reveal a promising method in the design of advanced Pt-based catalysts for direct methanol fuel cells.