Graphene-Carbon Nanotube Hybrids as Robust Catalyst Supports in Proton Exchange Membrane Fuel Cells. Issue 3 (7th January 2016)

• Record Type: Journal Article
• Authors: Pham, Kien-Cuong; McPhail, David S.; Mattevi, Cecilia; Wee, Andrew T. S.; Chua, Daniel H. C.
• Is Part Of: Journal of the Electrochemical Society. Volume 163:Issue 3(2016)
• Page Start: F255
• Page End: F263
• Publication Date: 2016-01-07
• Subjects: Carbon Nanotube -- Cathode -- Degradation -- Durability -- Graphene -- Hybrid -- PEMFC -- Platinum -- Proton Exchange Membrane Fuel Cell; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0891603jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Catalyst degradation is one major challenge preventing the worldwide commercialization of the Proton Exchange Membrane Fuel Cells. In this study, we investigate the development of a novel hierarchical carbonaceous support for the platinum catalysts, called graphene-carbon nanotube hybrids (GCNT), and its degradation behavior during an accelerated degradation test. The carbon support is fabricated by growing graphene directly onto carbon nanotubes to form a unique all-carbon nanostructure possessing both an ultra-high density of exposed graphitic edges of graphene and a porous structure of carbon nanotubes. The GCNT-supported platinum catalyst exhibits a higher intrinsic catalytic activity than a carbon black-supported platinum catalyst, and much higher than a CNT-supported platinum catalyst. The enhanced catalytic activity of the GCNT-supported platinum catalyst is explained by the high graphitic edge density which promotes the catalytic reactions on platinum catalyst. The GCNT-supported platinum catalyst also exhibits a superior electrochemical stability over that of the carbon black-supported platinum catalyst, explained by the high crystallinity of the GCNT support. The superior stability is expressed by a lower loss in polarization performance, a smaller increase in charge transfer resistance, a lower loss in the platinum electrochemical surface area, a lower rate of carbon corrosion, and a more stable catalyst microstructure.