Royal Society of Chemistry, Journal of Materials Chemistry A: materials for energy and sustainability, 19(2), p. 7015-7019, 2014
DOI: 10.1039/c4ta00091a
Full text: Unavailable
Nitrogen-doped CNTs directly grown on a carbon cloth (CNT/CC) hybrid with polybenzimidazole (PBI) are utilized as hybrid electrodes for high-temperature proton exchange membrane fuel cells (HT-PEMFCs). Pt nanoparticles (NPs) of typically 2.5 nm diameter have been deposited uniformly on the electrode composed of either CNT/CC or carbon black on carbon cloth (CB/CC). Comparative study of 0.1 mg cm-2 Pt NPs on a PBI-CNT (Pt/PBI-CNT) electrode and 0.8 mg cm-2 Pt NPs on PBI-carbon black (Pt/PBI-CB) for oxygen reduction in the cathode has been performed. In H2/O2 HT-PEMFC single cell tests, the low Pt-loaded (0.1 mg cm-2) Pt/PBI-CNT/CC electrode outperforms the high Pt-loaded (0.8 mg cm-2) Pt/PBI-CB/CC electrode with maximum power densities of 643 mW cm-2 and 468 mW cm-2, respectively, at 160 ?C. Notably, the Pt-loading of a Pt/PBI-CNT/CC cell is one eighth of that of the Pt/PBI-CB/CC cell, while the former outperforms the latter by approximately 38%. The enhancement is attributed to good interfacial continuity between the PBI membrane and the carbon cloth and the uniform dispersion of the catalyst on the PBI-CNT surface, leading to the formation of three-phase contacts, which is essential for the activity of the catalyst. Copyright 2014 the Partner Organisations.