International Journal of Hydrogen Energy, Vol.41, No.21, 9204-9210, 2016
Graphitic mesoporous carbon xerogel as an effective catalyst support for oxygen reduction reaction
Graphitic mesoporous carbon xerogel (GMCX) with high surface area and comparable mesoporous structure is prepared via a sol gel process with cobalt acetate, followed by the subsequent pyrolysis in nitrogen flow at 1800 circle C. 20 wt.% Pt/GMCX catalyst is synthesized using the as-prepared GMCX powder as support. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterizations for Pt/GMCX indicate that Pt nanoparticles dispersed on GMCX have a much smaller average nanoparticle size and narrower size distribution than Pt nanoparticles grown on commercial XC-72 carbon black and GCX powder which we reported before. The results of linear sweep voltammetry (LSV) test demonstrate that the Pt/GMCX catalyst exhibits a higher oxygen reduction reaction (ORR) electrocatalytic activity than commercial Pt/C and Pt/GCX. The corrosion resistance of the catalysts was evaluated by potential cycling accelerated aging test (AAT). Pt/GMCX catalyst exhibits very nearly the same Pt electrochemical active surface area (EASA) retention as Pt/GCX (53.3% for Pt/GMCX and 53.0% for Pt/GCX), which is higher than that of commercial Pt/C (39.2%). Combined with its facile synthesis process, GMCX powder is a promising substitute for commercial Pt electrocatalyst support in achieving high catalytic activity and good durability for ORR. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Carbon xerogel;Support;Durability;Oxygen reduction reaction;Proton exchange membrane fuel;cells