Nitrogen functionalized carbon nanotubes as a support of platinum electrocatalysts for performance improvement of ORR using fuel cell cathodic half-cell

Abstract

In many works of literatures, the performance of carbon nanotubes as Pt support has been studied in the oxygen reduction reaction (ORR). Here we demonstrate the impact of these carbon nanotubes after modification by nitrogen groups to improve the performance of ORR in PEM fuel cell applications. In this regard, the characterization results of bare (MWCNTs), and functional groups of nitrogen by triethylenetetramine (MWCNTs-TETA), diethylenetriamine (MWCNTs-DETA) and malononitrile (MWCNTs-MN)precursor were presented and then the electrochemical analysis of Pt nanoparticles depositing on them are studied. The role of nitrogen functional groups on the activity and stability of Pt nanoparticles is investigated. These parameters are investigated using catalyst coated membrane electrode (CCME) which is placed inside a homemade cathodic half-cell. The CCME is prepared with a Nafion 117 membrane and gas diffusion layer (GDL) having an active area of 0.785 cm2. The half-cell test results show that Pt/MWCNTs-TETA electrode had the highest ORR performance of 64.48 mW cm−2, while showed the lower ECSA drop than Pt/MWCNTs.