Silver Nano-particles Modification Used as Cathode Catalysts to Enhance Anion Exchange Membrane Fuel Cells

This research mainly explores the non-precious metal catalyst used as in the cathode electrode to improve the anion exchange membrane fuel cell (AEMFC) performance. Because nano-silver particles with excellent oxygen reduction reaction (ORR) characteristics and lower cost compared to Pt, they are good candidates for cathode electrode in AEMFC. Two approaches can realize the target to use Ag instead of Pt. It was implemented with processing Ag nano-particle, the resulted cell performance close to Pt with 3.5% difference. The other one is to modify Ag surface using cerium nitrate to enhance cell performance. In the experiment, the pickling Vulcan XC72R carbon black was used to increase functional group of Vulcan XC72R carbon black attached on their surface. It also can increase Ag nano-particles to integrate with the cathode substrate. The silver nitrate was reduced to Ag nano-particles through a chemical process for the cathode. Combined with the reducing agent ammonium cerium nitrate and the N₂ gas environment during the annealing of the furnace tube, the cathode catalyst with 40 wt% Ag nano-particles were completed. While platinum (Pt/C) (40 wt%) was mixed with isopropanol (IPA) and deionized water (DI) with a certain ratio for the anode. It was found to be 7:3 (IPA, DI) mixed with Pt/C for the anode and then 5:5 (IPA: DI) mixed Ag/C for the cathode. Through this study, it was found that the highest cell performance reached 623 mW/cm². It can implement non-precious metal catalyst, Ag nano-particles, to be used as cathode for AEMFC.