PtRu electrocatalysts on carbon nanotubes treated by phenylphosphonic acid for electrooxidation of methanol

Phenylphosphonic acid (PPA)-assisted one-pot method for preparation of PtRu nanoparticles with high dispersion and stabilization on carbon nanotubes (CNTs) is reported. Based on the π–π stacking between phenylphosphonic acid and CNTs, abundant phosphonate groups were uniformly introduced on CNTs' surface, which significantly not only improve the solubility and dispersibility of CNTs in polar solvents but also enhance the dispersion of PtRu nanoparticles on CNTs' surface. The obtained PtRu/PPA-CNT electrocatalysts are characterized by transmission electron microscopy, infrared spectroscopy, thermal gravimetric analysis, X-ray photoelectron spectroscopy, Raman spectroscopy, and X-ray powder diffraction. The results reveal that CNTs were successfully functionalized by PPA, and PtRu nanoparticles were uniformly dispersed on PPA-CNT surface with average particle diameter of 2.5 nm. Electrochemical studies certified that PtRu/PPA-CNT electrocatalysts have much higher electrocatalytic activity and stability for methanol oxidation in comparison with PtRu nanoparticles supported on the pristine CNTs because of their highly electrochemical surface area at 612.7 cm² mg^?1.