화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.162, No.7, F736-F743, 2015
Effect of Added Graphitized CB on Both Performance and Durability of Pt/Nb-SnO2 Cathodes for PEFCs
The single cell performances of polymer electrolyte fuel cells (PEFCs) using Pt catalyst supported on Nb-SnO2 (Pt/Nb-SnO2) with/without graphitized carbon black (GCB) were compared with that of a cell using Pt/GCB. The Pt-mass specific power of the Pt/Nb-SnO2 cathode under low humidity conditions was superior to that of the Pt/GCB cathode, because the hydrophilic SnO2 support helped to increase the proton conductivity of the iononner, which led to high Pt effectiveness. The addition of GCB to the Pt/Nb-SnO2 cathode improved the cell performance under high humidity, and the Pt-mass specific power value reached more than 10 kW g(Pt)(-1). The improvement conditions was attributed to the formation of gas diffusion paths by adding the hydrophobic GCB. The Pt/Nb-SnO2 cathodes, with/without GCB, had greater durability than that of the Pt/GCB cathode during the startup / shutdown potential sweep evaluation. The migration of Pt particles on the Nb-SnO2 support was suppressed by the high stability of Nb-SnO2 and. strong orientation between Pt and Nb-SnO2 support. The degradation of GCB in the Pt/Nb-SnO2 cathode was smaller than that in the Pt/GCB cathode because of the absence of Pt on the added GCB. Therefore, the added GCB was still able to provide gas diffusion paths even after extensive cycling. (C) 2015 The Electrochemical Society. All rights reserved.