Enhanced electrocatalytic performance of La modulated PtCo nanobunches for methanol electro-oxidation

In this study, we fabricated La modulated PtCo bimetallic networked nanobunches (La-PtCo NBs) consist of parallel aligned ultrathin nanowires approximately 2 nm in size through a convenient one-pot solvothermal method. The modification of trace La induced the formation of defect-rich surfaces and optimized the surface electronic configuration of Pt. It makes that more hydroxide is adsorbed on the electrode surface to form La-OH, which enable facilitate the breaking of the C-O bond and decreased CO adsorption at the Pt site. Moreover, 1D configuration can efficiently accelerate rapid electron diffusion and expose more utilizable active sites, thus achieving highly active electrodes for catalyzing methanol oxidation reaction (MOR). As expected, the La-PtCo NBs exhibit the superior mass activity of 1073.08/728.69 mA·mgPt−1 and specific activity of 144.60/98.19 mA·cm−2, which indicate improvements of 4.19 and 3.28 times relative to commercial Pt/C in acid and alkaline conditions. Besides, the mass activity loss of La-PtCo NBs is 83.60 % and 48.35 %, much lower than those of PtCo (88.75 % and 67.84 %) and commercial Pt/C (97.12 % and 72.38 %) after successive 10 000 s tests in acid and alkaline media, respectively. This work indicates a strategic design for remarkable improvements of efficient Pt based alloy electrocatalysts in fuel cell applications.