Platinum nanoparticles supported on carbon nanofibers as anode electrocatalysts for proton exchange membrane fuel cells

Abstract

Pt nanoparticles supported on carbon nanofibers (Pt/CNFs) with different microstructure, i.e., platelet CNF (Pt/p-CNF), fish-bone CNF (Pt/f-CNF), and tubular CNF (Pt/t-CNF) were synthesized by a chemical reduction method. X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) were applied to characterize the structure of the as-prepared catalysts. The electrochemical surface area (ESA) was studied by cyclic voltammetry (CV). Membrane electrode assemblies (MEAs) with the as-prepared catalysts were fabricated and tested. We found that Pt nanoparticles showed different particle size and dispersion on the three kinds of CNF supports and the mean size of the Pt nanoparticles on p-CNF, f-CNF, and t-CNF was 2.4, 2.7, and 2.8 nm, respectively. Single cell testing indicated that the cell with Pt/p-CNF as the anode catalyst gave better performance compared to Pt/f-CNF and Pt/t-CNF. The maximum power density was 0.569 W·cm-2 for Pt/p-CNF, which was higher than that for Pt/f-CNF(0.550 W·c m-2) and Pt/t-CNF (0.496 W·c m-2). Furthermore, Pt nanoparticles supported on carbon black (Pt/XC-72) were also prepared. Pt nanoparticles supported on CNFs have been shown to have a smaller particle size and better dispersion than those on XC-72, and this proves that CNFs can be an efficient electrocatalyst support for proton exchange membrane fuel cells (PEMFCs). © Editorial office of Acta Physico-Chimica Sinica.