Highly active platinum electrocatalyst towards oxygen reduction reaction in renewable energy generations of proton exchange membrane fuel cells

摘要

Reducing platinum usage and increasing its electrocatalytic durability are the key issues for the successful application of PEMFC. Fabricating platinum into specific morphologic structure and combining with the superior support is one of effective resolutions. In this paper, porous carbon nanofibers supported platinum nanowires (PtNW/PCNF) were synthesized via a simple and inexpensive template-free methodology and used oxygen reduction reaction (ORR) electrocatalyst. As a comparison, Pt nanowires supported on commercial carbon black (PtNW/Vulcan) was also prepared in the same condition. High-resolution transmission electron microscopy (TEM) shows that the single-crystal Pt nanowires were successfully grown on the support. The electrocatalytic activity and stability of the resultant catalysts along with the commercial one (JM20) were investigated by using cyclic voltammetry (CV) and liner sweep voltammetry (ISV) with a rotating disk electrode (RDE). As a result, the PtNW/PCNF exhibited much enhanced electrocatalytic activity and stability compared with the PtNW/Vulcan and JM20. The mass activity (at 0.80 V vs. RHE) of the PtNW/PCNF is about 1.7 and 2.3 times higher than that of PtNW/Vulcan and JM20, respectively. The remnant ECSA of the PtNW/PCNF after 1000 cycles was about 32% compared with the initial one whereas JM20 and PtNW/Vulcan retained only 10% and 23%. Furthermore, after ADT test for the three electrocatalysts, PtNW/PCNF lost 51 mV in half-wave potential, significantly better than the 150 mV half-wave potential loss for PtNW/Vulcan and almost complete loss of performance for commercial JM20. These results indicate controlled growth of Pt nanowires as a potential choice for conventional Pt nanoparticles and PCNFs a promising candidate as catalyst supports for the enhancement of PEMFC performance. (C) 2016 Elsevier Ltd. All rights reserved.