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Exfoliated graphene-supported Pt and Pt-based alloys as electrocatalysts for direct methanol fuel cells

Exfoliated graphene-supported Pt and Pt-based alloys as electrocatalysts for direct methanol fuel cells

Authors :
Jian Zhou
Rui Hao
Qiang Sun
Jun Jiao
Beth A. Manhat
Andrea M. Goforth
Micah Eastman
Wen Qian
Source :
Carbon. 52:595-604
Publication Year :
2013
Publisher :
Elsevier BV, 2013.

Abstract

To greatly improve the electrocatalytic activity for methanol oxidation, high-quality exfoliated graphene decorated with uniform Pt nanocrystals (NCs) (3 nm) have been prepared by a very simple, low-cost and environmentally benign process. During the entire process, no surfactant and no halide ions were involved, which not only enabled very clean surface of Pt/graphene leading to excellent conductivity, but also greatly improved the electrocatalyst tolerance to carbon monoxide poisoning (Pt/graphene, If/Ib = 1.197), compared to commercial Pt/C (If/Ib = 0.893) catalysts. To maximize the electrocatalytic performance and minimize the amount of precious Pt, Pt–M/graphene (M = Pd, Co) hybrids have also been prepared, and these hybrids have much larger electrochemically active surface areas (ECSA), which are 4 (PtPd/graphene) and 3.3 (PtCo/graphene) times those of commercial Pt/C. The PtPd/graphene and PtCo/graphene hybrids also have remarkably increased activity toward methanol oxidation (If/Ib = 1.218 and 1.558). Furthermore, density functional theory (DFT) simulations demonstrate that an electronic interaction occurred between Pt atoms and graphene, indicating that graphene substrate plays a crucial role in regulating the electron structure of attached Pt atom, which confirmed that the increased efficiency of methanol oxidation was due to the synergetic effects of the hybrid structure.

Details

ISSN :
00086223
Volume :
52
Database :
OpenAIRE
Journal :
Carbon
Accession number :
edsair.doi...........ed5dc148458ea431968bc01c8b6a2835
Full Text :
https://doi.org/10.1016/j.carbon.2012.10.031