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Pt–M@FP-MWNT catalysts (M = Ru, Ni, Co, Sn, and Au) were prepared by one-step γ-ray irradiation. Two different types of functional polymers (FP), such as poly(vinylphenyl boronic acid) (PVPBAc) and poly(vinylpyrorridone) (PVP), were used as anchoring agents, when Pt–M nanoparticles were deposited on the multi-walled carbon nanotube (MWNT) using γ-ray irradiation in aqueous solution at room temperature. The obtained Pt–M@FP-MWNT catalysts were then characterized by XRD, TEM, and elemental analysis. The catalytic efficiency of the Pt–M@FP-MWNT catalysts was examined for CO stripping and MeOH oxidation for use in a direct methanol fuel cell (DMFC). The catalytic efficiency of the Pt–M@FP-MWNT catalyst for MeOH oxidation follows this order: Pt–Sn@FP-MWNT > Pt–Co@FP-MWNT > Pt–Ru@FP-MWNT > Pt–Au@FP-MWNT > Pt–Ni@FP-MWNT catalysts. The CO adsorption capacity of the Pt–M@FP-MWNT catalyst for CO stripping is as follows: Pt–Ru@FP-MWNT > Pt–Sn@FP-MWNT > Pt–Au@FP-MWNT > Pt–Co@FP-MWNT > Pt–Ni@FP-MWNT catalyst.

This paper describes the electrocatalytic activity for CO, MeOH, and EtOH oxidation on the surface of Pt-Ru nanoparticles supported by metal oxide (Nb-TiO2-H) prepared for use in a fuel cell. To prepare Nb-TiO2-supported Pt-Ru nanoparticles, first, the Nb-TiO2supports were prepared by sol-gel reaction of titanium tetraisopropoxide with a small amount of the niobium ethoxide in polystyrene (PS) colloids. Second, Pt-Ru nanoparticles were then deposited by chemical reduction of the Pt4+and Ru3+ions onto Nb-TiO2supports (Pt-Ru@Nb-TiO2-CS). Nb element was used to reduce electrical resistance to facilitate electron transport during the electrochemical reactions on a fuel cell electrode. Finally, the Pt-Ru@Nb-TiO2-H catalysts were formed by the removal of core-polystyrene ball from Pt-Ru@TiO2-CS at500∘C. The successfully prepared Pt-Ru electrocatalysts were confirmed via TEM, XPS, and ICP analysis. The electrocatalytic efficiency of Pt-Ru nanoparticles was evaluated via CO, MeOH, and EtOH oxidation for use in a direct methanol fuel cell (DMFC). As a result, the Pt-Ru@Nb-TiO2-H electrodes showed high electrocatalytic activity for the electrooxidation of CO, MeOH, and EtOH.

Pt-Ru catalysts based on functional polymer-grafted MWNT (Pt-Ru@FP-MWNT) were prepared by radiolytic deposition of Pt-Ru nanoparticles on functional polymer-grafted multiwalled carbon nanotube (FP-MWNT). Three different types of functional polymers, poly(acrylic acid) (PAAc), poly(methacrylic acid) (PMAc), and poly(vinylphenyl boronic acid) (PVPBAc), were grafted on the MWNT surface by radiation-induced graft polymerization (RIGP). Then, Pt-Ru nanoparticles were deposited onto the FP-MWNT supports by the reduction of metal ions usingγ-irradiation to obtain Pt-Ru@FP-MWNT catalysts. The Pt-Ru@FP-MWNT catalysts were then characterized by XRD, XPS, TEM ,and elemental analysis. The catalytic efficiency of Pt-Ru@FP-MWNT catalyst was examined for CO stripping and MeOH oxidation for use in a direct methanol fuel cell (DMFC). The Pt-Ru@PVPBAc-MWNT catalyst shows enhanced activity for electro-oxidation of CO and MeOH oxidation over that of the commercial E-TEK catalyst.

Pt–Ru particles were loaded onto spherical polythiophene balls (PThB) and new catalysts, Pt–Ru@PThBs, were prepared. Pt and Ru ions were subjected to chemical reduction using NaBH4 as reducing agent or γ-irradiation in the presence of PThBs. The size, morphology, and composition of Pt–Ru@PThB catalysts were determined by transmission electron microscope (TEM), X-ray diffraction (XRD) and elemental analysis. TEM images of the Pt–Ru@PThB catalysts clearly provide evidences that Pt–Ru alloy nanoparticles are dispersed onto the surface of PThBs. The electrocatalytic efficiency of Pt–Ru@PThB was tested for electrochemical oxidation of carbon monoxide as well as for methanol. Pt–Ru@PThB catalyst prepared by γ-irradiation exhibits the enhanced electrocatalytic oxidation of CO and methanol. We envisage that Pt–Ru@PThB catalysts are suited for direct methanol fuel cells.