Carbon nanotubes as support of well dispersed platinum nanoparticles via colloidal synthesis

• Published in: Journal of power sources 2013-12, Vol.243, p.88-94
• Main Authors: Escobar, B., Barbosa, R., Miki Yoshida, M., Verde Gomez, Y.
• Format: Article
• Language: English
• Subjects: Applied sciences; Carbon nanotubes; Catalysis; Catalysts: preparations and properties; Chemistry; Colloidal dispersion; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical active area; Electrochemical conversion: primary and secondary batteries, fuel cells; Electron microscopy; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; General and physical chemistry; Pt/MWCNT; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2013.05.123

Pt colloidal nanoparticles were synthesized by simultaneous chemical reduction of metallic salts in presence of poly (N-vinyl-2-pyrrolidone) as protecting agent. The uniform and highly ordered Pt colloidal nanoparticles were associated to well dispersed particles ranging in particle size distribution around 4.5 ± 1.9 nm. The nanoparticles were deposited onto multiwalled carbon nanotubes (MWCNT). MWCNT were synthesized by chemical vapor deposition (CVD) method. Before the metal impregnation, the MWCNT were treated with HNO3 in reflux. Prepared Pt catalyst were characterized by various physical and electrochemical techniques, that is, X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy and cyclic voltammetry (CV). Raman spectroscopy reveals changes intensity ratio IG′/IG in the samples, after the cleaning process and Pt loading, indicating changes in the crystallinity of the materials. HRTEM showed Pt particles between 6.1 ± 0.9 nm and 6.5 ± 1.5 nm are well dispersed along the carbon nanotubes. XRD patterns show characteristics peaks corresponding to graphite and metallic Pt. The electrochemical properties of the MWCNT supported Pt nanoparticles were investigated by analyzing the response of the nanostructured catalyst for cyclic voltammetry and compared with a commercial material. [Display omitted] •The Pt nanoparticles shows spherical shape with a good distribution.•Pt colloidal nanoparticles were supported onto carbon nanotubes.•The size of the Pt nanoparticles was between 6.1 ± 0.85 and 6.5 ± 1.5 nm.•X-ray diffraction shows diffraction peaks corresponding to graphite and metallic Pt.•Electrocatalytic activity of Pt/MWCNT was higher than the Pt/C.