Elaboration and characterizations of platinum nanoparticles supported on cellulose-based carbon aerogel
Résumé
This work investigates the deposition of Pt nanoparticles onto carbonized aerocellulose (CAC), via impregnation of the CAC with H2PtCl 6 followed by reduction either under H2 at 300-400°C or in a basic NaBH4 solution. H2 reduction yields uniform Pt nanoparticles (average diameter < 2 nm) dispersed over the CAC surface, as revealed by transmission electron microscopy (TEM). Larger agglomerates can be seen in TEM images for NaBH4 reduced samples, which is confirmed by powder X-ray diffraction (XRD). A rotating disk electrode was employed to analyze the electrochemical properties of the Pt/CAC materials. The active area of the platinum nanoparticles was evaluated using hydrogen adsorption/desorption cyclic voltammetry and CO-stripping measurements. The oxygen reduction reaction kinetic parameters of the Pt/CAC materials compare well with those of commercial Pt/Carbon Black (CB). Finally, PEMFC unit cell testing demonstrates that a Pt/CAC electrocatalyst synthesized using 3 successive impregnation/reduction steps can compete with state-of-the-art Pt/CB electrocatalysts