H_xMoO_3-assisted deposition of platinum nanoparticles on MWNTs for electrocatalytic oxidation of methanol

摘要

Platinum nanoparticles were loaded on multi-walled carbon nanotubes (MWNTs) by using ethylene glycol as reductant and with the assistance of hydrogen molybdenum bronze (H_xMoO_3,0 < x ≤ 2) for the electrocatalytic oxidation of methanol. In this approach, MWNTs were modified by H_xMoO_3 and used as the support for platinum nanoparticles. The XRD and TEM characterizations indicate that the average particle size of platinum supported by the modified MWNTs (Pt/H_xMoO_3-modified-MWNTs) is 3.4 nm, smaller than that (4.3 nm) of the platinum supported by the unmodified MWNTs (Pt/MWNTs). The voltammetric and chronoamperometric experiments show that Pt/H_xMoO_3-modified-MWNTs exhibits better electrocatalytic activity toward methanol oxidation than Pt/MWNTs, although the former has a less platinum loading (4.6 wt%) than the latter (6.0 wt%). The mechanism on the assistance of H_xMoO_3 to the platinum deposition was discussed.