Single walled carbon nanotube in the reaction layer of gas diffusion electrode for oxygen reduction reaction

Abstract

In this paper, the effect of surface area of reaction layers in gas diffusion electrodes on oxygen reduction reaction was investigated. For this purpose, various amounts (0.1, 0.2, 0.3, 0.4, 0.5, 1, 1.5 and zero %wt of total loading of reaction layer) of single walled carbon nanotube (SWCNT) were inserted in the reaction layer. The performance of gas diffusion electrodes for oxygen reduction reaction was studied in a three-electrode half-cell system, via linear sweep voltammetry (LSV), cyclic voltammetry (CV), chronoamperometry (CHA) and impedance analysis. The results show that, the existence of SWCNT in the reaction layer improves the exchange current density of ORR, the symmetry factor changed between 0.51 and 0.83, as a whole in the optimized condition (0.4% wt .SWCNT) tendency of gas diffusion electrode for ORR is increased. The addition, influences significantly in electrochemical surface area and the gas diffusion electrode with 0.4%wt SWCNT has lowest charge transfer resistance respect to other electrodes. Our results indicated that the best performance obtains for an electrode with 0.4% single walled carbon nanotube.