Synthesis and characterization of Pt nanoparticles on sulfur-modified carbon nanotubes for methanol oxidation

• Published in: International journal of hydrogen energy Vol. 36; no. 12; pp. 7275 - 7283
• Main Authors: Ahmadi, Rezgar, Amini, Mohammad K.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-06-2011; Elsevier
• Subjects: Alternative fuels. Production and utilization; Applied sciences; Carbon nanotubes; Catalyst support; Catalysts; Dispersions; Energy; Exact sciences and technology; Fuel cell; Fuels; Hydrogen; Methanol oxidation reaction; Methyl alcohol; Nanoparticles; Oxidation; Platinum; Pt nanoparticles; Sulfur; Carbon nanotubes; Pt nanoparticles; Methanol oxidation reaction; Sulfur; Fuel cell; Catalyst support; Particle size; Hydrogen; Nanoparticle; Supported catalyst; Characterization; Transmission electron microscopy; Platinum; Preparation; Nanocomposite; Oxidation; Pretreatment; Surface area; X ray diffractometry; Catalyst activity; Nanostructured materials; Methanol
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2011.03.013

Pt nanoparticles supported on carbon nanotubes (Pt/CNTs) have been synthesized from sulfur-modified CNTs impregnated with H
2PtCl
6 as Pt precursor. The dispersion and size of Pt nanoparticles in the synthesized Pt/CNT nanocomposites are remarkably affected by the amount of sulfur modifier (S/CNT ratio). The results of X-ray diffraction and transmission electron microscopy indicate that an S/CNT ratio of 0.3 affords well dispersed Pt nanoparticles on CNTs with an average particle size of less than 3 nm and a narrow size distribution. Among different catalysts, the Pt/CNT nanocomposite synthesized at S/CNT ratio of 0.3 showed highest electrochemically active surface area (88.4 m
2 g
−1) and highest catalytic activity for methanol oxidation reaction. The mass-normalized methanol oxidation peak current observed for this catalyst (862.8 A g
−1) was ∼ 6.5 folds of that for Pt deposited on pristine CNTs (133.2 A g
−1) and ∼ 2.3 folds of a commercial Pt/C (381.2 A g
−1). The results clearly demonstrate the effectiveness of a relatively simple route for preparation of sulfur-modified CNTs as a precursor for the synthesis of Pt/CNTs, without the need for tedious pretreatment procedures to modify CNTs or complex equipments to achieve high dispersion of Pt nanoparticles on the support.