ISSN 2456-0235
INDEXED IN
International Journal of Modern Science and Technology, Vol. 2, No. 1, 2017, Pages 1-7.
Pt–Ru–M/MWCNTs (M = Ni, Mo and Rh) Nano-catalysts for membraneless fuel cells: Effect of the pretreatment on the structural characteristics and perborate electro-oxidation
K. Vijayaramalingam1, S. Kiruthika2, B. Muthukumaran1,*
1Department of Chemistry, Presidency College, Chennai – 600 005, India.
2Department of Chemical Engineering, SRM University, Chennai – 603 203, India.
*Corresponding author, e-mail: dr.muthukumaran@yahoo.com
Abstract
The synthesis, characterization and activity of Pd–Ir–M (M = Ni, Mo and Rh) electrocatalysts supported on multi-walled carbon nanotubes leading to enhancement of the electrocatalytic oxidation of sodium perborate is presented. The combination of monometallic Pd/MWCNTs, bimetallic Pd–Ir/MWCNTs and tri-metallic Pd–Ir–Ni/MWCNTs, Pd–Ir–Mo/MWCNTs and Pd–Ir–Rh/MWCNTs electrocatalysts were prepared by the ultrasonic-assisted chemical reduction method. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and X-Ray diffraction (XRD) were used for the catalyst characterization. The synthesized electrocatalysts have been similar particle morphology and their particle sizes were 3-5 nm. The EDX results of the binary Pd–Ir/MWCNTs and the ternary Pd–Ir–Ni/MWCNTs, Pd–Ir–Mo/MWCNTs and Pd–Ir–Rh/MWCNTs catalysts were extremely close to the nominal values, indicating that the metals were loaded onto the carbon support without any obvious loss. The performances of the electrocatalysts have been examined in half-cell experiments using cyclic voltammetry (CV), CO stripping voltammetry and chronoamperometry (CA). The electrochemical results obtained at room temperature showed that the tri-metallic Pd–Ir–M (M = Ni, Mo and Rh) electrocatalysts displayed better catalytic activity toward sodium perborate oxidation compared to the other catalysts. In this study, the binary Pd−Ir/MWCNTs and ternary Pd−Ir−M/MWCNTs (M = Ni, Mo and Rh) anode catalysts were effectively tested by using single membraneless fuel cell using 0.15 M sodium perborate as the fuel and 0.1 M sodium perborate as the oxidant with 0.5 M H2SO4 as the electrolyte respectively. Based on the experimental results, we conclude that the Pd−Ir−Ni/MWCNTs demonstrate superior sodium perborate electro-oxidation than Pd−Ir−Mo/MWCNTs, Pd−Ir−Rh/MWCNTs, Pd−Ir/MWCNTs, Pd/MWCNTs.
Keywords: Multi-walled carbon nanotubes; Palladium; Iridium; Nickel; Membraneless sodium perborate fuel cell.
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