Electrocatalytic oxygen reduction on single-walled carbon nanotubes supported Pt alloys nanoparticles in acidic and alkaline conditions
- 264 Downloads
The objective of this study is to improve the catalytic activity of platinum by alloying with transition metal (Pd) in gas diffusion electrodes (GDEs) by oxygen reduction reaction (ORR) at cathode site and comparison of the acidic and alkaline electrolytes. The high porosity of single-walled carbon nanotubes (SWCNTs) facilitates diffusion of the reactant and facilitates interaction with the Pt surface. It is also evident that SWCNTs enhance the stability of the electrocatalyst. Functionalized SWCNTs are used as a means to facilitate the uniform deposition of Pt on the SWCNT surface. The structure of SWCNTs is nearly perfect, even after functionalization, while other types of CNTs contain a significant concentration of structural defects in their walls. So catalysts supported on SWCNTs are studied in this research.
The electrocatalytic properties of ORR were evaluated by cyclic voltammetry, polarization experiments, and chronoamperometry. The morphology and elemental composition of Pt alloys were characterized by X-ray diffraction (XRD) analysis and inductively coupled plasma atomic emission spectroscopy (ICP-AES) system. The catalytic activities of the bimetallic catalysts in GDEs have been shown to be not only dependent on the composition, but also on the nature of the electrolytes. The GDEs have shown a transition from the slow ORR kinetics in alkaline electrolyte to the fast ORR kinetics in the acidic electrolyte. The results also show that introduction of Pd as transition metal in the Pt alloys provides fast ORR kinetics in both acidic and alkaline electrolytes. The performance of GDEs with Pt–Pd alloy surfaces towards the ORR as a function of the alloy’s overall composition and their behavior in acidic electrolyte was also studied. These results show that the alloy’s overall composition and also the nature of the electrolytes have a large effect on the performance of GDEs for ORR.
KeywordsPlatinum Alloy Oxygen reduction reaction Gas diffusion electrode Alkaline electrolyte Acid electrolyte Carbon nanotubes
- 2.Komai YJ (1998) Exp Biol 201:2359–2366Google Scholar
- 6.Tarasevich MR, Sadkowski A, Yeagar EB (1983) In: Conway BE, Bockris J.O’M, Yeagar EB, White RE (Eds.), Comprehensive treatise of electrochemistry, vol 7. Plenum Press, New York, p 301Google Scholar
- 7.Kinoshita K (1992) Electrochemical oxygen technology. Wiley, New YorkGoogle Scholar
- 8.Adzic RR (1998) In: Lipkowski J, Ross PN (eds) Electrocatalysis. Wiley-VCH, New York, p 197Google Scholar
- 9.Markovic NM, Ross PN Jr In: Wieckowski A (ed) Interfacial electrochemistry-theory, experiments and applications. Marcel Dekker, New York, p 821Google Scholar
- 15.Taylor EJ, Vilambi NRK, Gelb A (1989) J Electrochem Soc 136:1939–1949Google Scholar
- 34.Kannan AM, Shukla AK, Sathyanarayana S (1990) Bull Electrochem 6:273–281Google Scholar
- 35.Ross PN Jr (2003) Handbook of fuel cells: fundamentals, technology and applications. Wiley, p 465 (Chapter 31)Google Scholar
- 37.Adzic RR (1998) Electrocatalysis. Wiley–VCH Inc., New York, p 197Google Scholar
- 39.Pourbaix M (1966) Atlas of electrochemical equilibria in aqueous solutions. Pergamon Press, London, pp 108–117Google Scholar