Facile one-pot synthesis of graphene-porous carbon nanofibers hybrid support for Pt nanoparticles with high activity towards oxygen reduction

Abstract

Graphene-porous carbon nanofiber (G-PCNF) and Graphene-carbon nanofiber (G-CNF) hybrid materials were prepared by the one-pot modified Hummers method followed by thermal annealing as the unique Pt nanoparticles supports for oxygen reduction reaction (ORR). Particularly, 1D PCNF and CNF can be spacers for 2D graphene (G) to make full utilization of the high intrinsic surface area of graphene and the Pt nanoparticles can be uniformly deposited on the hybrid supports, resulting in excellent activity for ORR. The newly developed Pt/G-PCNF and Pt/G-CNF catalysts exhibit higher activity compared to the Pt/G catalyst. The electrochemical activity and durability of Pt/G-PCNF as well as the commercial catalyst Pt/C (JM20) were also researched. The ORR results show that the onset potential of Pt/G-PCNF is 38mV higher than JM20 and the mass activity (at 0.8V) is twice higher than JM20. Pt/G-PCNF also demonstrates better stability, maintaining 50.4% of its electrochemical active surface area (ECSA) after accelerated durability testing (ADT) whereas JM20 only retain 17.0%. Furthermore, the half-wave potential of Pt/G-PCNF loses about only 9mV, significantly superior to the 154mV half-wave potential loss for JM20. These results indicate that G-PCNF can be a promising candidate as highly promising class of catalyst supports for the improvement of electrochemical activity of proton exchange membrane fuel cells (PEMFCs).