화학공학소재연구정보센터
Journal of Applied Electrochemistry, Vol.40, No.3, 675-681, 2010
Structural optimization of gas diffusion electrodes loaded with LaMnO3 electrocatalysts
In this study, gas diffusion electrodes (GDEs) with two catalyst layers were fabricated and tested for their electrode performance for oxygen reduction in an alkaline solution. The LaMnO3/carbon black catalyst layers were fabricated using a reverse micelle method to finely disperse the LaMnO3 particles onto the carbon matrices, for which commercial Ketjen Black (KB) (1270 m(2) g(-1)) and Vulcan XC-72R (VX) (254 m(2) g(-1)) were used. The three-layer-structured GDE with the two LaMnO3/KB and LaMnO3/VX catalyst layers exhibited a superior oxygen reduction activity when compared to that of a conventional GDE with only one LaMnO3/KB catalyst layer. Pore size distribution and gas permeability measurements revealed that the LaMnO3/VX layer was more porous and had higher gas permeability than the LaMnO3/KB layer. These results suggest that the intermediate layer of LaMnO3/VX can efficiently supply oxygen to reaction sites dispersed in the LaMnO3/KB and LaMnO3/VX catalyst layers, which consequently leads to an improvement in the electrode performance.