Double-Walled Carbon Nanotubes as an Electrode for Direct Methanol Fuel Cell Applications

• Published in: ECS transactions Vol. 16; no. 50; pp. 113 - 122
• Main Authors: Tang, Shuihua, Sun, Gongquan, Sun, Shiguo, Qi, Jing, Xin, Qin, Haarberg, Geir Martin
• Format: Journal Article
• Language: English
• Published: 29.08.2009
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/1.3157942

Double-walled carbon nanotubes (DWNTs) supported platinum catalyst exhibited good activity and stability for oxygen reduction reaction (ORR). This can be attributed to its high specific surface area, relatively high crystallization and special network which can facilitate electron transfer, water removal and oxygen or air access to the catalyst active sites. The pore size distribution profile of DWNTs showed it had large part of mesopores which is favorable for mass transportation, X-ray diffraction patterns indicated that DWNTs is better in crystallization than the most used commercial carbon black XC72R. Platinum particles were uniformly distributed on the surface of DWNTs and its average size was 2~3 nm even for the nominal 60 wt% Pt/DWNTs catalyst. The actual Pt loading was 54.9 wt% calculated by scanning electron microscopy coupled with element dispersive spectroscopy (SEM-EDS) result for this 60 wt% Pt/DWNTs catalyst. Pt/DWNTs catalyst demonstrated better oxygen reduction activity and single-cell performance than commercial Pt/XC72R catalyst (from Johnson Matthey company) under identical conditions, and the single-cell performance was quite stable when it was discharged at constant current of 100 mA/cm2 for 20 hours.