A NEW GAS DIFFUSION ELECTRODE (GDE) WITH A BETTER O۲ REDUCTION ELECTROCATALYSTS WITH VERY LOW PT CONTENTS VIA NANO-SIZED PT-COATED NAFION

In the present study, a new gas diffusion electrode (GDE) (based on Pt/Nafion membrane) is fabricated. The electrochemical results show that the new GDE has the highest electrochemical activity toward the oxygen reduction reaction (ORR) among the three electrodes. The SEM and XRD findings show that a platinum layer can be attached to Nafion membrane closely and firmly with a strong peak corresponding to (۱۱۱) crystalline face. The results illustrate that placing a Pt monolayer on a Nafion membrane is an attractive way of designing better O۲ reduction electrocatalysts with very low Pt contents. Under optimum conditions, Tafel slope, exchange current density (i۰), and charge transfer resistance (Rct) are obtained to be respectively equal to ۸۵ mV dec-۱, ۲×۱۰-۳ A, and ۸ Ω. For this electrode, the platinum particle size is ۴ nm.

Keywords:

Oxygen Reduction Reaction , Nafion Membrane , Platinum Monolayer , Gas Diffusion Electrode , SEM , XRD