Heat-treated platinum nanoparticles embedded in nitrogen-doped ordered mesoporous carbons: Synthesis, characterization and their electrocatalytic properties toward methanol-tolerant oxygen reduction

Fabrication of N-doped ordered mesoporous carbons containing well-dispersed and methanol-tolerant Pt nanoparticles (Pt-NOMC) via an easy route is reported in this paper. These Pt-NOMC samples invoke the pyrolysis of co-fed carbon sources and Pt precursor with various carbonization temperatures (Pt-NOMC-T) in 3-[2-(2-Aminoethylamino)ethylamino]propyl-functionalized mesoporous silicas which were simultaneously used as N sources and hard templates. A series of different spectroscopic and analytical techniques was performed to characterize these Pt-NOMC-T catalysts. Combined the results from X-ray diffraction, N2 adsorption–desorption isotherms, transmission electron microscopy and elemental analysis show that ca. 0.7–2.2 wt% of nitrogen was successfully doped on the high surface areas of ordered mesoporous carbon rods. Further studies by X-ray photoelectron spectroscopy indicated that Pt-NOMC-T catalysts with different ratios of quaternary-N and pyridinic-N were observed. Among various Pt-NOMC-T samples, the Pt-NOMC-1073 sample, which may be due to moderate electrical conductivity of ordered mesoporous carbons, unique nanostructure between Pt nanoparticles and N-doped carbon supports, and presence of more pyridinic-N atoms, was found to possess superior electrocatalytic activity for methanol-tolerant oxygen reduction in comparison with the typical commercial electrocatalyst (Pt/XC-72).

► A novel route to synthesize well-dispersed and nanosized Pt particles supported on N-doped carbons. ► The synthesized materials possess high ORR activity and surpassing methanol-tolerance. ► This may be due to the dispersion and unique nanostructure between Pt nanoparticles and N-doped carbon supports.