Catalytic activity of platinum—cobalt alloy nanoparticles decorated functionalized multiwalled carbon nanotubes for oxygen reduction reaction in PEMFC

摘要

The role of functionalized multiwalled carbon nanotubes (MWNTs) decorated with platinum nanoparticles (Pt/f-MWNTs) and platinum-cobalt alloy nanoparticles (Pt_3Co/f-MWNTs) has been investigated for oxygen reduction reaction (ORR) in a proton exchange membrane fuel cell. The electrocatalysts are synthesized by a conventional sodium boro-hydride reduction method and modified polyol reduction method. The modified polyol reduction method yields better uniform dispersion, higher loading and optimum particle size of Pt and Pt_3Co alloy nanoparticles over the MWNTs compared to the conventional sodium borohydride reduction method. The electrochemical surface area of the electro-catalysts is calculated using cyclic voltammetry. Pt_3Co/f-MWNTs synthesized via modified polyol reduction method yield the highest performance with a maximum power density of 798 mW cm~(-2) at 60 ℃ without any back pressure. The enhanced catalytic activity of Pt_3Co/ f-MWNTs toward ORR is attributed to uniform dispersion and optimum particle size of Pt_3Co alloy nanoparticles over the surface of/-MWNTs.